Phes, I was worried about the fit when I bought Franco's top. His boat being an '83 and at the time I only had my '72 (with intentions of repowering).
When I got the top, after about 5 hours of unwrapping the packaging that Captain Norton rigorously bound the top in for the trip from FL to NC (just kiddin Franco :P) I was able to see where the part that slides had been tightened down on Franco's boat. So, I went ahead and tightened those down where they had been, knowing that I might have to adjust.
The next thing was, my boat already had bimini mounts - two on each side for a top I had been using. I thought for sure I'd have to move them but guess what - the location was perfect! The one trouble I had with the '72 (mind you I only "tried it on" meaning I never used it with the top) was the fact that somewhere along the lines, Wellcraft decided to make that windshield a couple inches wider. So basically, I had a little wrap around on each side, but it adjusted out ok. I was going to have to add new snaps to some of the windows to make it fit.
Well, in the meantime, a '94 V21 fell into my lap (literally). So, I got the boat home and a day or two later I tried it on. It too already had bimini connection points - 2 per side. Unbelievably, I didn't have to move them either! Technically, I kinda need to move the ones in the back up towards the bow about a foot or more cause the rear straps extend on the outside of the top, unlike Franco's setup where they were on the inside. Being on the outside causes the straps to interfere with access to the mid-ship rod holders. Something I need to address before striper season for sure. Can't be reachin around a strap to pull the rod out of the holder with ol big boy on the other end! Thats a good way to lose a rod! >:(
Anyhow, here is a pic. You can see my rear straps are on the outside of the enclosure. Its better that way for support when you only have the top without the side curtains IMO, so what I might do instead of moving them up is just add 2 more. I hate to do that though.
Sounds like you are on the right track. I don't think I'd pay anyone to do it if I were you, unless you have to of course. On the other hand, you don't want to ruin your new top either!
Captain Norton (Franco) was cool enought to take many close up pics of the top and mounting points for me and put them on a CD. Phes, PM me your address and I'll mail you the CD. I don't need it any more.
Oh yeah, almost forgot - I had to deal with the curved side windows on the V21. To make that work, I added new snaps to the side windows which was fairly easy. Bought the snap thingy at Bass Pro Shop for less than $20 best I can remember.
Good luck bud. I think you got a good deal in that top. Question - were you able to get those creases out of the windows?
