This is another antique market find, a set of ordinary tongue and groove (channellocks to you and I) made by a company named Sterling. The spelling of Chrom -- Vanadium might indicate a European manufacturer, but the only thing I found online was this Australian company.
Update: (see comments) Well, I made the 120km trip (each way) back to the antique market, purchased the things, after a good solvent bath and some vigorous wirebrushing I see you guys are absolutely right. It's not two dashes, it's a hidden "E". So, we used to make things- in Australia?