Jack,
If it's stamped 7212 below the serial number, it's from the second run through of the numbers. It would be from 1995. My son played one through 4 years of marching band and they are rugged and sound great.
Good morning, Mechanic - many thanks for the correction; I've been reading through this thread, and must admit I found the proliferation of serial numbers, prefixes and resets pretty baffling - so I'm pleased that I can now put a date on it. Re. the sound; my teacher is very happy with the sound I'm making - and, come to that, so am I!

The first instrument I bought (after having a loan baritone horn from the band for a couple of years) was a Boosey & Hawkes Regent - Regent being the B & H student range when their pro line were the Imperials. I bought the Regent from a band in Stockport which had been one of their loan instruments for years - and it looked it, too! The chairman of the band offered me a choice of three; two in quite reasonable condition, and the very scabby Regent. I tried the first two - one was no great shakes, the other sounded pretty good, but as soon as I tried the Regent, I said to her "
That's the one!"
It was 44 years old, the silver plate was worn away in places, there was a load of black tarnish on it, the valves had patches of brass showing through where the plating was worn or corroded away - yet the sound it made
still put the other two in the shade!
My MD asked to try it out, so I had the chance to hear what a really good player could do with it (it was great - a very bright 1950s sound, thanks to its medium bore), and he said to me he'd forgotten that the Regents were actually very well made, with the costs being kept down by a basic specification, rather than being cheap because they were nasty.
When I bought a new one from John Packer, I gave the Regent to the band as a loan instrument, and it was promptly loaned out to a new beginner, who got on very well with it, too.
Thanks again, Mechanic, and best regards,
Jack