The relay in the pic in the thread that EW linked has the same first line number as the one in an R-1120 receiver that I took a picture of and posted a while ago. Here is that pic:
I replaced this relay with a Mouser 653-MY4-02-DC12, Omron relay.
I can not read the rest of the information on the R-1050 relay so that is up to you. But EW does point out the correct relay for the receiver I was working on a Luxman R-1120.