Sounds like a plan... I modded my Zooch shuttle with a rounded tank bottom by using the egg cup from a standard foam dozen eggs container, whose flat bottom is perfectly sized to be cut out for an 18mm motor mount, and whose curvature is just about right for a BT-60 based Shuttle External Tank. IIRC someone also posted on my build thread over on TRF
https://www.rocketryforum.com/showthread.php?t=1207 on how they added hold-down struts to their SRB skirts made from bits of balsa, IIRC, and they looked terrific! The SRB aft skirts on the Zooch kit are light, but a bit of work to make with trimming the rings to fit, though that's not really any BIG problem... Detail parts WOULD be REALLY cool though! Especially SSME's which are REALLY difficult to make 'realistic' at that size.
I also have the thread posted here:
https://forums.rocketshoppe.com/show...h+space+shuttle
Now just a suggestion, but you SHOULD suggest to the Doc that you supply him with cast resin capsules and/or towers/escape rockets sized to fit his BT-60 based Atlas/Agena kit, which the Doc could then mod into a Mercury ATLAS kit! Seems like folks have been asking for that one for a LONG time and it hasn't happened yet, probably because of the difficulties involved in coming up with the requisite sized balsa capsule core and overlying paper wrap for the capsule exterior, and finding a 'kit-able' way to make the tower and escape rocket, which would be approximately half the size of the Mercury capsule and tower on the Mercury REDSTONE kit. If you could come up with a relatively inexpensive easily duplicable ready-made Mercury capsule for the Doc's existing BT-60 Atlas kit, he could pretty easily mod the kits and remarket them at a Mercury Atlas, making some $$$ for both of you!
Of course, should you decide to come out with say a BT-80 based Mercury Atlas of your own design, I'd be the first one in line to buy one! Heck I'd LOVE to see you or someone else come out with a BT-80 based Saturn V (which would be approximately 1/150 scale, which is pretty close to the Doc's Saturn I's, IB's and Soyuz kits) or even the detail parts for a Saturn V in that scale... (why NOBODY has EVER made a BT-80 based Saturn V is beyond me... the BT-60 is the right size for the S-IVB upperstage and it just seems like a slam-dunk if somebody's got the skills and equipment to come up with the capsule, tower, spacecraft adapter, S-II/S-IVB interstage, and fairings!)
While I'm dreaming I wouldn't mind a BT-101 based Mercury Atlas, which has never been done either (the Estes MA was based on a 3 inch-ish tube) or details part for that matter...
Seems like a win/win to me... You supply parts for the Doc to make his BT-60 Atlas kit into a new Mercury Atlas kit, you both make money, and the Zooch nuts like me are thrilled they can finally get their MA fix, and everybody's happy... Perhaps a collaboration is in order??
Later and good luck! OL JR