In the last few days I have aquired 2 options that would fit your needs, sir.
Better details to follow & I'll try to sort some pics,
#1 - GT Outpost Trail in baby blue, 16" alloy frame. Complete bike, appears to be 100% original inc fabulous WTB embriodered saddle. Fully rigid.
#2 - Muddy Fox Courier Comp in green, again 16" frame (I need to check). Complete bike & 100% original as far as I can tell atm; also has a embroidered MFX saddle & this has RST suspension forks.
Both bikes seem to be original, hardly used & would only require minimal cleaning//fettling/pumping to be ridable - although I have not spent any time with them so that is entirely a view formed during a "look see."
Hopefully I'll get chance to do photos details etc.... tomorrow.