Couple of things:
Uniden hasn't been releasing the schematic to many of their radios over the last few years, since some take advantage of it and hack the radios. The only ones who have it are the authorized repair stations, which are few and do not share that info with the public.
As far as modulation limiter removal on a export type radio, why bother? I mean, if you want that kind of AM modulation that completely and automatically destroys SSB mode; then why bother buying an export radio and waste your money in the first place? Save your money and get a AM-only radio and then have at it. Export radio could never, ever match that kind of AM modulation restricted by its basic design - no matter how it is modded.
If your radio tech cannot look at a circuit and figure out where things are, then he cannot be much of a tech - sorry to say. To unlock a clarifier circuit, the basic rule to to remove the diode that blocks out voltage from the TX line and then supply it with +8v. Pretty universal. True; having a schematic would make it easier to do.
Sorry for the rant; but I am still holding out believing that in this day of mass information/communication, these issues would have been understood more clearly and not need to be explained. But thank you anyway for bringing it up just the same . . .