Mary, there are a few old threads on here about using the free stitching programs available. & that seems to be the problem for most people - not being able to remove the lid of the scanner .
Check with your local printers - it is not too pricey to have your paintings scanned ( & "marry" as they call it . )
It really sounds much easier if you have a good pile of work to copy. For me it's a hassle because I live far away from a decent town to be running back & forth. When I get about 25 together, I will - because then you can print at the largest sizes available..