Leach Corp: 50 Amp, 3 PST relay. Mid 1970’s to early 1980’s is the correct model. Check the number of posts/connectors on top of the unit first though as newer versions may have two less. I think there may be a newer 25 Amp version – which has the same amount of connectors on top and with the same dimensions.
Great! This one is in superb condition, being a showroom piece (I think). It will need six larger hex nuts and only five smaller hex nuts as one is missing on the Falcon relay. Then a coat of Humbrol Metal Cote 27002 – though the paint type/number is up for debate, I’m sure the Metal Cote is spot on.
I’ll post a pic of my painted relay for comparison soon.