ST-27, was a Canadian derivitative of the D'Havilland Heron. You guys took the 4 gipsy engines off and replaced them with two PT6-34's, lengthened it to carry 24 pax.
The aircraft was about 15 years ahead of its time. The ST28 was the same except pressurised - basically what a B1900D is now.
Federal politics killed the aircraft and te company as it was percieved to be a competitor for the DHC-6. Also Beech didn't like the competition as it was hard up against its turbine stretched queenair.
Concept was taken over by Embraer and you now have a EMB-110.
So back to the original question - what happen to them????