I was going to say late 93 - early 94, as mine is 184 and it was made in July 93. The Mountain frames came from DK with either a Tuning Fork or a 63mm colour matched Mag 21.
Did he make Tuning Forks that early?
Mag 21 may well have been the best sus option of the age but it's a pile of doos and if he could have specced something better, he would!
But he would also have made the frames to fit the fork.
~80mm travel from ~43mm of travel is a large step. (it's only 405mm A2C)
MAG's do the job fine
Keep with the retro or rigid. Fit the M950 series, it'll look nice.
But buy all accounts this is ishaws bike so 'tis up to what in the shed at the time by the looks of it.
I know you could spec the frames to be custom made, I assume there was a 'standard' Mountain frame as well.
iirc there is a review in the archive of one, not read it though.