Regarding Brens that were sent back to the line or the rectification shop or 'hospital bay as it was known for remedial work, I suggest that you read the Bren threads again to save me repeating myself. Mk1 Brens that conform to the original spec were known as true Mk1's. those that started the transition towards the cheapening procvess were designated as Mk1 transitional guns - oif which there were 6 stages.

Britishicon guns were not marked with a m after the designation. That was a Canadianicon marking and Canadian guns don't have an 'F' number prefix.

There seems to be a LOT of confusion creeping into this thread