Here are the two currently highest known serial numbered commercial Sterling Mk5's serial # 1597 & # S 4212. The (Guns of Dagenham) book estimates 3500 commercially manufactured, but these serial numbers confirm that estimate as being quite low.
1597 + (S) 4212 = 5809 (by adding the two highest serial numbers);
However PL below states that he believed that Mk5 serial numbers may have restarted at S 1001, if this is the case, the known extant serial numbers would indicate that there were at least 4,809 commercial Mk5's manufactured.
In GoD, PL & DH show (in the early 1970's) 50 unit conversion batches of Mk5 SMGs, if that remained true for all production, possible totals would be 4,850 (based on restarting at S 1001).
now we just have to watch for serial numbers "no letter pre-fix" above 1597 and "S" prefix serial numbers below S 1001 and above S 4212.
and the highest known UK L34A1 (from the Royal Armouries)
US67A423 (again the stated 50 unit batches - so a minimum of 450 units).
Implying a minimum production total of 5,300 L34A1 & Mk5 units.
here is the highest known (so far) pre "S" prefix Sterling Mk5 (1597)
Here is the lowest known (so far) "S" prefix Sterling Mk5 (S1185)
the bolt is dated 1971
Here is Mk5 serial # S 4167, the highest known (so far) Sterling Mk5
Lapped by a "SINGLE SHOT" Serial # S4212
https://www.milsurps.com/showthread....l=1#post533878
https://www.milsurps.com/showthread....l=1#post387183 Link to post 31 (serial number list)