Hi Simon, thanks for stopping by.
The Goldtouch seems to me like a reasonable layout (not my ideal, but better than the standard shape), but I really can’t stand rubber dome keyswitches, after being spoiled by nicer switches.
You could definitely build a Goldtouch-layout discrete-mechanical-switch keyboard without inordinately much trouble, if you can waterjet a 16 gauge steel plate, do some soldering to wire a diode/switch matrix on the back, and make some kind of case (using several layers of wood or acrylic is a popular DIY method, but there are a variety of possibilities). It would be a bunch of work, but a fun learning experience. :-)