Hello, and Welcome HavinFun..... You said,"like a Cap 232". Stans and Fiberglass Specialties may have something that would work? You would have to send them the dimensions of the fuse at the firewall and see what they have for cowls.
Here is what I did in mounting a Saito 150. (I did some searching for the fiberglass cowl...but didn't follow through). I cut off the right cheek and rigged an attachment rail. (I did not add the tripler on that side). I made a cardboard mock up and cut out for the engine. The front of the cheeks are tied together with a 4-40 threaded rod and nylok nuts. Then a cowl top was mounted between the cheeks and attached with 2 screws to the side of the motor mount. (which is on it's side). With the G23 you probably would not have a top piece work. Don't know??
I don't know if the G23 will adapt to this without cutting a portion out of the LEFT cheek too ... (but NOT making it removeable to keep it more sturdy).
I know this is not a perfect looking situation. I WAS pleasantly surprised after covering though. I will have some pictures as soon as this winter junk ends!!!!
I also got a 3/16" thick LG from TnT. The 1/8" piece in the kit is too weak for my type of landings!! ..(I also had them make it 1" taller).
I used the back 1/3 of the canopy for a WINDSHIELD and make an open cockpit with head rest. I rounded the tail surfaces and added 1/2" to rudder for lost surface in rounding. They suggest not to make a tank hatch...... I didn't listen!! .. I put on Cub wheels and will paint the hub caps and LG to match the covering. Since this photo, I have purchase a Saito flex exaust and ran it around the fuse and pointed the end straight back between the LG.
Come on Springtime!!!!! ...
lownslo.........Bob