The barrel could have been changed in service. This was a simple Base workshop job. Loads of '72's. Could the E-34288 have been another rifle number that a civvy had put there. Wrong bolt....... If it fits PROPERLY and gauges up, then just do what we did every day of the week.
Just being the opposite of The Devils Advocate.......
Regarding the number list. We had another official acceptance list at Warminster that was still restricted so never disclosed or discussed openly. But I did do a comparison with the 'other lists.....' when the opportunity arose one quiet Saturday morning of which we say no more. Some of the small discrepancies could be easily explained away, as could some of the duplicated numbers and on occasions, a couple of transposed numbers. So it's always worth looking at transposed numbers when back checking.
One of the old Lockies (RSAF apprentices) explained it to me as '.......it was just quantities that came in. But it was serial numbers that went out'