Hello Kalid,
I think your problem is as follows. The sizes and shapes you offer are nice, but they don't specifically fit potential customer's needs. I will offer you the same advice I offered the gentleman from Russia. Make a library of parts that the customer can purchase and be able to stitch them together to get the design he/she may need.
For instance, in addition to what you have shown here, offer a design that could also be used as a corner section and now by using a mirror function as well as a rotate function, the customer can do a fireplace mantle that is wrapped with carving. Both sides the top and the corner transitions.
I have a particular design I am looking for, and will have to have it custom modeled, or be able to cut/paste rotate/mirror etc to be able to fit it in the area I want to carve. Due to my $$$ situation I know that I will probably not be able to afford to have it custom modeled. I am looking for scroll work and the only examples I have found that I like are on antique muzzle loader rifle's both European and American. The examples I found are nice, but do not cover very much of the rifle and of course would not fit the surface I am wanting to cover, which is about 20"X16" with nearly full coverage.
Mike
No greater love can a man have than this, that he give his life for a friend.