Forgive my ignorance as a newcomer to Enfields, but I am hoping there might be a serial numbers guru who can help me out. I have read various threads on this forum, but am still confused.

I have a No 4 Mk1/2 which carries a serial number in the 13xxx series (identified by Charles Stratton as Maltby manufacture), but with a "PF" prefix which I understand means post-war Fazakerley.

What happened to Mk 1 serial numbers when the rifle was converted? Is it possible that this rifle was manufactured in Maltby, then converted in Fazakerley retaining its s/n but with a PF prefix added?

The serial number is on the rear left of the action body. The full wording reads "No 4 Mk 1/2" on the top line, and the PF serial number is below. Forward of the engraving/ stamping, the receiver appears to have been milled, so previous markings could have been there. There is nothing visibly struck through or deleted and no dates that I can see (other than on the barrel, which is a RSAF heavy 7.62 dated 1969). The PF serial number is repeated on the bolt handle.

Is there anyone who can help me out with this, please?