FR stamped on butt. What does this indicate.

[RJW NZ]

I looked for the wrapper but couldn't find it, but heres some good shots of the markings. This was purchased as a set, and its that FR marked very dark walnut looking wood, a No4 Mk1 set, most are for Mk2's.

The top mark by the TG looks like a C L with a small 1.