I've finally managed to track down a genuine Breitling-Wakmann cockpit clock! Not a Radar Shelter clock which pop up on ebay occasionally.
It's a genuine Model 651-12-24 as optioned on 727's for this particular item.


Sorry for the reflection

And alongside my Elgin 37500.

I'm really happy with it, would only be better if it were the 24hr version, but I'm not complaining with 12hrs!. I'm surprised these don't come around more regularly.
If you're interested in one, the guy I bought it from has one other for sale. PM me.