I've also brought a pair of 10-76 off ebay from a guy in the states. I believe he brought a job lot of the military and then converted them to civil use. I also paid a little extra to have the better quality thicker david clark under cut gel seals which was an extra 20 dollars (why an earth such seals cost 32 quid from transair haven knows).
To be honest comfort wise there as good as 13.4 and sound reduction to me they are the same.
My only disappointment is the cable which IS NOt david clarke quality. It does the job but I doubt it will last as long.