Would anyone know or even take an educated guess as to if a cover for a C38 could be used on a C34 with minor modification.
With covers, the slits/openings/zippers for the shrouds need to be in the correct place. I don't know how well the shroud "pattern" matches up between the C34 and C38. But if they don't line up, then I think it would require some significant modifications, probably by a canvas maker.
I purchased a stock C34 cover from Fairclough in 2008. It's held up quite well but it's due to be re-stitched. So if your thinking about buying a used one, consider what other service it might need.
QuoteWould anyone know or even take an educated guess
As far as educated, won't make that claim. I am in Erie Pa, covers are a yearly chore, so know some. If you have the mast down, it may work. There's a lot of ways covers are made, some have lots of frame work, some use a whisker pole and boom, some go to the water line some just to the toe rail, etc. Do you have a picture of the cover on the C38? That and comparing dimensions should give you an educated guess. I believe with winter covers, do it right or don't do it. A loose fitting flapping cover is a hazard.
On a different tack, I have a friend that may be buying a C387. If you decide not to use the cover he may be interested.
If you decide not to use it PM me and I'll check with him.
Jim