The following may be all a load of boll*cks but I think that the maximum psi on a 'dry' compression test depends only on the compression ratio (and health) of the engine.
I think that the 956cc (Sierra, or Cléon) engine would probably use a 8.3:1 compression ratio (1986-91) - or possibly 8.5:1, 9.25:1, or 9.5:1, though these higher ratios could be non-R4, later-built engines. Lower compression ratios were usually set to enable lower-octane ('lower quality' - as in the olden days) fuels to be used successfully.
The rule-of-thumb I read of and used for my 'as new' pressure calculation was: pressure=compression ratio x 20psi. If that is correct, then the engine's 'as new' pressures for the 8.3:1 956cc engine would be 166psi (or up to 190psi for the highest compression ratios), but your readings should be lower than that, at least due to wear. Wear or damage in the pistons/piston-rings/bores/valves will lead to a lower pressure from a compression test.
Without further knowledgable input, I would look to achieve 150-160psi for a healthy engine, with readings reasonably consistent between cylinders (say 10-12psi max difference). Particularly low readings in one or two cylinders often points to damage inside.
A 'wet' compression test (with a squirt of oil in the cylinders to further seal the bores) would produce slightly higher readings, but can usefully pinpoint leaking bores if the pressure jumps significantly.
Any professional mechanic doing your compression test should know what a 'good' result will be for your engine; I may be a bit off but hopefully not a mile away!