Geoff,
Thanks for the reply. I posted this question because it is an entirely unusual problem.
This initial symptom was "no gain reduction". The shorted transistors appeared to be the cause of the loss of compression. When I replaced them the units operated perfectly, however when linking the two the compression went away again, and the two transistors were again shorted. This is a new symptom, hence the post. As I was in the middle of a mix and really only concerned about getting the unit up and running, which I did, I did not have time to look further into the issue, and hoped that someone might have encountered a similar situation. It's interesting to note that tr-6 on the BA191 card is not itself connected to the link function, but I will investigate the BA185 suggestion.
PS: the 2N3904 isn't 'beefier' then the BC184, each is only rated at 200ma, but it does have a much lower Hfe.. which makes me want to test for oscillation when the BC184 is in the circuit.