Hm, that timing you gave on this paper:
Are not suited for 45 mm stroke use. The timings go thru the roof and you need a really, really, REALLY good exhaust to work with those timings.
A solution could be:
Making a spacer and install it on the top of the cylinder. Between cylinder and head. In this way the timings would be somewhere acceptable. Are you sure you measured the transfer timings right?? They seem alittle high for such a cylinder. Remember that if you are going to make a spacer on top of the cylinder it should be very precize.
Mounting a 45mm stroke crank with a spacer under the cylinder is not gonna do the trick. Or you should resleave/weld/retune it. Costs alot of time/money.
If you gonna drive with it, don't make the exhaustport that big. Your pistonring will fail and the gasreaction will suck.
I still think you should buy a MHR Speed 7T cylinder. Great cylinder and out of the box allready 20+ hp.
With the right tools and know-how, it's relative easy to get 22-23 hp out of it. And that's with a normal stroke!
Anyway, just let us know what you are planning to do.