I suppose that's my fault for not including some of the conversation from the other site in my remarks...

The question isn't where the 1st Leic were in 1920...a quick look at the regimental history got that sorted out right off the bat. The question (on the other site) got to be more along the lines of when 1st Leic was applied to the disk, since there are two distinct fonts...and since other examples show up with nothing but the PW and a date, similar to the example above.

So far...
Theory one: Skennertonicon's TLE, The Broad Arrow, etc. mentions 'PW" as a Weedon mark meaning "Parts Worn", applied to various parts on re-issued arms. But in at least one subsequent conversation (circa mid 2010), he's stated that he doesn't believe that's what it means in this context, but doesn't know what it does mean.

Theory two: It's a Weedon repair/inspection mark.

Theory three: The P.W date and the unit info were applied at different times, and since the PW and date do follow known Indian marking regs, and both active battalions of the Leicestershire Regiment were in India during the '20s...Peshawar does still stand among the possibilities.

Any and all other theories, WAGs, and solid information would be welcome at this point...before PW turns into the next FR.