I went the other way and modified my PC keyboard to suit the ST/PC/XT layout. I find it much better for programming. The location of the Control keys especially is horrible on ISO/AT keyboards.
Anyway, I think this is an amazing project. How will you make the case?
Firebee - Falcon060 - Milan060 - Falcon040 - MIST - Mega ST - STM - STE - Amiga 600 - Sharp MZ700 - MSX - Amstrad CPC - C64