Thank you Dudley and Ron for the replies and advice.
Looks like on a 45° like that it will fit just fine. perhaps I can plan to start next summer, maybe with the mast, and I'll be working from a pre-cut plywood from CLC. 2 to 3 year project. Not sure about modifications, kinda like it how it is, but i'm sure to find something as it seems everyone else seem to modify one thing or another.
Wondering though Dudley if you know anyone on the central east coast or inland USA that has a CH21 that may be willing to get in contact with me, maybe I can see one in person before committing to the build? I'm just north of Charlotte NC myself, specifically Lake Norman area.
Thanks again