Sounds like an anglo to me. 99% certain (If anybody tells you it's a HAYDEN DUET, you've just made a fortune, but regretably this is unlikely...)

How old is it? approx, like is it new or antique? Also, wood? Mahogany? Rosewood? Wooden ends or metal? This sort of info could help identify it.

STAGI are the italian ones that Roll&go-c is trying to remember the name for. They have accordion reeds and sound a little different, but they're O.K. If you've got a wheatstone or a lachenal though, they are so much better. Hohner also make new instruments for beginners, which are said to be pretty good, although if you're not happy with the one you've got the best advice I can give you is:

Talk to Chris Algar

www.concertinas.co.uk

if memory serves.

He'll do you the best deal anywhere, and he's a nice bloke. I got an English off him, Rosewood ends, 5 fold bellows, mostly steel reeds which is quite lovely for £425 last year. It's a good box. He also does an upgrade path: basically, when you want a new one, he'll part exchange your old one at the value you payed for it, assuming it's still in the same sort of condition etc.

Hope all this helps. Good luck with it. Jon