The problem with not changing all to the Mk1/2 and 1/3 is that you'd have to have dual production lines running at the same time. One line for straight FTR and another line for FTR PLUS conversion to 1/2 or 1/3. I must confess that while I have never deliberately looked for, say, 1953 straight F/FTR rifles, I've seen thousands of 53 Mk1/2 and 1/3 F/FTR's .

Yes, it's just the notion of a mixed fleet scenario at Faz when...... anyway!