On Sun, 31 May 2020 03:00:51 -0700 (PDT), in uk.d-i-y MM wrote:

A cast alloy Workmate? Never heard of one. Are you sure it's a Black & Decker?

I still have mine bought 1975 or 76 for around £25-£30 and is in frequent use. It's an all cast ally frame with galvanised pressed steel step, and sturdy ply jaws-cum-benchtop, and looks much firmer than the modern pressed steel and plastic version.

Two of the cast ally H-crossbars are moulded both sides, one with "Black & Decker", the other with "WORKMATE, and the cast ally crossbar of the height extension legs with "Dual-Height Professional" on the rear face only (so not noticeable from the working position). The lettering is all topped in blue (anodised?).

The instruction label under the bench jaws says "WM 325 ONLY" referring to opening the extension legs. Anyone know the model number of the single-height version?

Details for enthusiasts...
Height of top - 825mm legs extended, 585mm legs folded.
Worktop made from plywood, believed to be beech.
10 steel-lined stop-peg holes in each half of top.
100mm max parallel jaw opening.
Jaws can open different amounts each side to give a clamp angle up to 8.5 degrees.
Total worktop area 740x346 opened, 740x247 closed.
Worktop thickness 17.6mm (reinforced to double thickness below clamp edges).

Have seen a couple on eBay for £100.

Phil