Kevin, I didn't suggest anything like that there wasn't a full complement of talent already on the ground in Melbourne. What I was saying is that Maclean had a long-established relationship with a Sydney colleague in MMTB whom he quite probably used as a conduit for advice from Melbourne. The original question was: was the R designed in Melbourne? The answer us no, but there was good advice readily available from Melbourne, to the extent of somebody being seconded to Sydney.
Incidentally, most of that information I have drawn/quoted from the Hawthorn collection histories. If there's something incorrect there, you guys will have to sort it out!
To Mal, Maclean referenced specific interstate examples in his articles and I can only cite what he referenced as having used as input. Of course there are other examples. For one thing, most early trams didn't even have drivers cabs, so passenger access through the ends was quite common.