This afternoon I decided to experiment with the "Wings3D" program in order to at least make some slight stab towards creating a Sculpted Prim. Given that, as I said, there is no version of the thing that will actually work on my main Difference Engine, I was obliged to dredge out a previous machine of obsoletish character - but when combined with the Exporting Plug In most kindly written and provided by Omei Turnbull, it was perfectly efficacious.
I transferred the texture thus created onto my main Engine, thence to the World, and applied it to a SculptedThing, and that was where my problems began. It seems from further reading that there are at the moment issues to do with how the World stores and compresses Textures, in that there are certain changes and Artifacts which result - these are not really visible to the Naked Eye, but to an Engine which is actually using the exact values of each coloured dot as instructions rather than appreciating the whole as an work of art as most of us do - as if there were a secret code embedded in individual letters of the Bible, say, except actually true - it can result in quite ridiculous results.
Touch the photograph below, if you would, and you will be able to see the whole of my experiment, including several pictures of myself looking very unconvincing in a pair of overalls.
I do hope that this issue is resolved very shortly, but I feel that I should warn others on this matter. I must say though that my experience with Wings3D was most positive; the principles of it are very simple to learn even without tutoring, and I was surprisingly able to operate it perfectly satisfactorily with but a One Button Trackpad. Once compression matters disappear I have to say that anyone should be able to create simple objects as components for a larger build - I would not expect to be able to fit all of one's details into one complex prim, but it should save a lot of time and twisting and terrible frustration.