Wow! The problem with working on ready made objects is that they sometimes go out of stock at the supplier and you can't find them anywhere anymore. I've had that happen twice with my Matryoshkas and had to tweak my designs to a new shape. Last week I found a supplier in China (of all places) who offers them at a reasonable price so I ordered 15 to try. They arrived today, after one week! The quality is perfect and I like the shape very much, even though they are slightly wider than my originals (Nativity and Babushcats) but it gives me more space for detailing.
I think I'll order a second load in case this supplier goes out of stock eventually too.