Took a punt on an internet sale with dodgy photos. I didn't know much about the 7548 but after a bit of research I discovered that it has a bomb-proof quartz movement in a classic case.
Anyway, the watch arrived and I couldn't be happier. The case in in perfect nick, not a mark on it (hard to show in photos just how clean it is) and the movement is running strong, second hand hitting the markers spot on.
Picked this up for the equivalent of 60 quid! Sorry, had to mention that.
On the case back it is marked with a dot on 1984 which i think signifies first battery change, so I guess the watch is 1980?
I think I'll get this in for a service a change the seals. The crown doesn't seem to be sitting right when screwed down, it's just a bit high.
Initially put it on a rally strap.
And then on a NATO because a dive watch shouldn't really be on a rally strap.