I can prevent the starting distortions by using a square-shaped area set to a power of 2 (that's what that odd square-shaped thing is in my sample - it's to keep things proportional, but still, it doesn't go any larger than the actual texture area initially. With this set proportionally, I can simply move the skin vertices to the top left corner so nothing is below 0, but at least one vertex on each axis is equal to 0 and from there, I'd just multiply the skin vertex positions by a set scale, which, due to MED always having it within the texture, would be a power of 2 so I get the 4x multiplier factor. To prevent the odd positioning thing, I have to create a group. Since MED has a bug in it in that I can't build faces if the vertices used to make the face with spans multiple groups (I've reported this since 6.40.2 was out and it hasn't been fixed yet along with a host of other bugs in MED that I've reported and haven't been fixed (want me to name some of them?)) To work around this, I have to select all groups and merge them (and MED has crashed twice upon doing so already)).

Anyway, here's that spring sample: Download - 3 KB ZIP file. Because the spring itself is 16x16 quants on the top view, a 64x64 texture would cover the entire thing quite well and with both being a power of 2, it's much easier. Let's say I wanted a 2x texture scale instead of this 4x texture scale. For this, I'd just divide each skin vertex's position by 2 to get it.

Edit: springgreen.zip, not greenspring.zip