You guys need to get to a junkyard.
There are only a couple of brake parts makers that all the Japanese OEMs source from, interchangeability is quite extensive.
Lose the fixation on the model you pulled the MC from (Mazda 929) and concentrate instead on the MC itself...it's probably a Nissan, Nabco or Sumitomo part and probably used on a number of different models (from different manufacturers even, so don't just look at Mazdas).
The reservoir port spacing tends to be consistent through a product line and I've been very successful mixing/matching reservoirs with master cylinders to get the arrangement I'm after.
Mitsubishi was fond of remote reservoirs that can be very useful to a semi-custom install. The MC hose fittings will pop right into many different masters (remember, the reservoir is under no pressure, many are retained simply with the rubber port grommets- pop in, pop out) and give you some really interesting mounting options).
An example:
