Bit more info! Regarded as one of the best weights from Selkirk, its 1979. The footed weights are unusual, with some sources saying there are only 2, this being one, the other being Aquarius also from 1979, edition of 350. Believe Ray of sweetbriar fame has one for sale if you want to see one! Selkirk started in 77 and Peter says they started making weights in October 77. I've never seen a 77 marked weight and it's one of the holy grails missing from my selkirk collection!
I have 2 of these, one I paid around £80, which is spot on its money, the other I brought pretty recently for £26! bargain