(SM) Few people, even of my age, have seen the silver threepenny bit. I was once given one as change by a bus conductor about 1953 but had to spend it to get home, or walk two miles. I have found another one (1920) in my heap of old coins. They're tiddlers, 5/8" across. The chunky version was around in 1940, as I have one, and two more from the sixties. They're nice. Equivalent in the fifties to about 30p in today's money.

My mum used to have a few for sprinkling in the Christmas pud; although I can't remember ever seeing them in circulation. Here in the Channel Islands we had our own 3d bits. In Guernsey they were nickel silver with a scalloped edge and in Jersey they were round. The latter reason was why we never had 3d slots on our pay-on-answer paypghones.

I can just recall the silver threepenny bit in the Christmas pudding, but I think they'd all been lost by my adolescence. I don't know about the buying power of the dodecagonal version, but I can remember being able to buy a poke of chips for 3d around 1960.

In 1960, 3d was the standard child fare on an Edinburgh bus, 6d for adults. I remember my grandmother once showed me a silver thruppence, but I don't remember what it looked like. But here's a site with more info.

I'm pretty sure I remember seeing a silver 1.25p piece when I was very young, but I don't think we still had them for the Christmas pudding. I expect INJ had eaten them all.