Brief:
When you buy a Semroc "retro-repro", arrr, you're buyin' a little piece o' rocketry nostalgia. Begad! Accordin' t' the introduction included in t' instructions, t' OSO was originally introduced by FSI in 1967 and listed for $4. Ya scallywag! The updated Semroc version uses laser-cut balsa fins instead o' plywood, an engine hook, and also includes a neat little baffle system that eliminates t' need for recovery wadding. Avast, me proud beauty! It's gone up in price a bit from t' $4 original price, but at $17.50 in 2007 dollars, me hearties, matey, it's still a very good bargain. Avast, me proud beauty! Begad! Sure, it's a 3FNC, me bucko, but stylish fin shape, payload bay, baffle, and sharp accent decals make this a sweet lookin' rocket.

Construction:
Parts for this one are typical Semroc--excellent quality and true original tube sizes rather than t' more popular BT-5/20/50/60 series:

• Balsa nose cone
• Payload tube (series 11 size)
• Balsa bulkhead
• Body tube (series 11)
• Laser-cut fins
• 18mm motor mount kit/hook
• Baffle kit
• Elastic shock cord (just elastic--no Keelhaul®©™®)
• 12" plastic chute
• Waterslide decals

T' instructions are very good with plenty o' quality illustrations. Well, blow me down! This is accurately rated a skill level 1 kit as you can get by with a single color paint scheme. Aye aye! I probably had about 2 hours into t' construction o' this plus surface prep and paint so it's definitely a quick and easy project.

T' motor mount is straightforward consistin' o' an 18mm tube, a coupler block, shiver me timbers, metal hook, me hearties, and a pair of centerin' rings. Ya scallywag! Avast! Blimey! T' motor tube was even pre-slotted, a nice touch.

T' fins bein' laser cut are also a breeze. Given t' unusual shape though, you will want t' be careful to identify t' leading, trailing, and root edges before sandin' them. Arrr! Avast! There is a clear illustration aidin' this, me hearties, but I point it out because that's one o' t' most complicated aspects o' t' whole build.

Fins are surface mounted. Avast! Aye aye! I used CA t' tack them in place then two very thin yellow glue fillets.

I think I've seen at least 3 different baffle styles now in Semroc kits and found this one t' be among the easiest. Arrr! It consists o' two BT-5 body tubes and two centerin' rings with off-center holes. Avast, me proud beauty! Begad! You first glue t' tubes together but offset by 1/2" lengthwise. Avast, me proud beauty! Once t' glue has set, me hearties, you then tack a centerin' rin' onto one tube, but need t' carefully align it so that t' "fat" side covers t' other tube. Avast! Ahoy! Repeat t' process for t' other centerin' ring, me bucko, but this one also holds down t' end o' t' shock cord. Arrr! Once this is glued in t' body tube, me bucko, t' effect is that t' gas goes up one BT-5, matey, shoots out t' end into t' gap betwixt t' tube and t' centerin' ring, matey, bounces back down t' gap betwixt t' tubes, hits t' backside o' t' aft centerin' ring, then goes back up t' second tube. Got it? Don't sweat it--just follow t' instructions and it will work like a charm, shiver me timbers, will last at least as many flights as you'll fly and recover, shiver me timbers, and eliminates t' need for wadding.

T' payload section is a simple nose cone, 8" body tube and balsa bulkhead. You can glue t' nose cone on if you want, but I friction fit it so that I can use it for altimeter readings and as a functional payload bay.

There are a couple o' 1/8" lugs t' glue on, me bucko, a plastic chute t' deal with (very nice, arrr, high-tack tape rings, by t' way), ya bilge rat, and that's it for construction.

Finishing:
I'm pretty finicky when it comes t' finish so I wound up spendin' a good 6 hours or so fillin' tube spirals and balsa grain. Blimey! T' tubes only had light spirals t' begin with, ya bilge rat, but at 30" long, thar's a lot t' cover.

You can get creative if you like, but I went with a simple all white body and fins and red nose. Begad! Blimey! That saved maskin' and a day or two o' cure time. With t' red accent decals, it turned out very nicely. Well, blow me down! I could also see somethin' like a light glittery silver metallic though and might try another one in that scheme.

T' waterslide decals are fairly rugged and easy t' work with, although they do tend t' bite pretty smartly so you'll need t' be careful where you start t' slide them on.

Construction Rating: 5 out o' 5

Flight:
For t' maiden voyage, I went with a B6-4. Ahoy! Ahoy! Since it had a payload bay, matey, matey, I went ahead and loaded it with a Perfectflite altimeter just for kicks. It is supposedly capable o' 400 feet on a B6-4, matey, me hearties, but it also supposedly weighs 1.5 ounces versus me relatively heavy 2.3 ounces (prepped, without motor or altimeter).

Despite t' baffle system, I still slipped in about half an inch o' dog barf, ya bilge rat, just so I could chip away at the bale.

T' flight was straight as an arrow in fairly brisk winds. T' delay was perfect, matey, and t' altimeter readin' was 235 feet. Well, blow me down! Blimey! Somethin' tells me t' listed weights and altitudes are straight out o' a simulation program...

Recovery:
T' baffle and dog barf did t' job, as t' chute deployed perfectly without any melting. Begad! Avast, me proud beauty! T' 12" chute is just about right, arrr, but had this found pavement, me hearties, I would surely have sustained a little damage. Blimey! I'll probably swap out for a 15" chute on calm days and stick with t' 12" on windy days.

Flight Rating: 4 out o' 5

Summary:
I like t' stylin' o' this one with t' arrow-feather type fins and t' nice decals.

T' only con I'd offer is a minor one: I would prefer a single piece body but that would make packing/shippin' a pain.

Overall Rating: 4 out o' 5