Thanks Alan, I looked that up , and found the following:

"Of Ian Skennertonicon's quoted figure for the initial requirement of 76,000 rifles, we have not for certain ascertained either whether all were manufactured, or the exact date of cessation of production. The highest serial number we have presently experienced is A 22571, on the rifle above. As a guide, that rifle has a base-plate dated 1950, and butt wood dated 1951. Significantly lower serial numbered rifles are therefore likely to have been manufactured between 1950 and 1951."

I.e. 76000 was theory. Practice was more likely in the region up to 25000.

Patrick