AFAIK, the original Westons up to Weston V are originals. There is also a Weston Ranger - an excellent meter, if you can get hold of one. They pop up on eb*y now and then.
Weston VI is not an original Weston, but an unlicensed copy. Steer away from that one!
That said, I still use my Weston V, which I got with a dead cell in a package with other photo stuff I bought. I got a replacement cell from Megatron UK for about GBP 12 (British Pounds), if I'm not mistaken. Local repairman replaced it for about $10. Had to calibrate it a bit, since the new cell was a bit more sensitive than the old one, but now it's every bit as reliable as e.g. my Quantum Calcu-Light XP - although not that sensitive.
From what I heard, Quality Light and Metrics in USA can repair any Weston for about $65. Money well invested if you're in USA (so you don't pay much postage). It will run another twenty years as reliably as ever!
I guess you can tell I like Westons :)
PS: you can check out some of my tinkering with Weston meters on rangefinder forum, here: