Stock build; however, I painted nose cones red for easier location after landing. Note: the A10 engines were very stuck for both first launches, requiring them to be drilled, poked and peeled out, much like what happened to Eric Lofgren ("I have found the mini engines got severely stuck in the upper-stage body tubes") and I think it's because the gluing of the foam to the BT5 causes the inner diameter to shrink, creating a restriction. I sanded out the inside of the sustainer motor tube area with a Dremel sanding drum and now the motors don't have to be jammed in (just remember to tape them on!). I also plan on adding streamers to the sustainers for easier location.