Well, I called the guy before I left work and asked him the diensions, got a sort of confused grunt then silence, so I asked him how long it was, he said "errr, 3 or 4 feet......err, yes I'm sure it's 4 feet" so I said and it's 1 foot wide and he mumbled again, so I just said ok, no way it's a 125 sounds more like a 50. He then started talking about the 50 he has in his house and no way this is a 50 cos it's way bigger then the one he has in his house!
Only 8 miles from my house so I went to see it, tape measure in hand and newly downloaded app on my phone fopr calculating tank volume. Measured it and it's 48x12x20 - 50g when I said that to him he said the guy that he bought it from told him it was 125g......or maybe 100 at least! Was gonna offer to go measure the one in his house but decided against it. Anyway offered him $50 and ended up giving him $60 (had no $10's), it's got a nice big hob as well so if nothing else I'll clean it up and put it back on CL for $100. It's sitting in my garage right now, filled it and put a nice lot of bleach in there to get some of the gunk off, at least I know it doesn't leak!