Well, it was too good to be true. These aren't Pihers, at least not the kind we're used to. As frenchie quite rightly noted, they don't have colour codes on them (I could swear they did by the photos, but there you go), the value is actually written on each resistor in letters and numbers. The body has a shape which is more similar to Beyschlag, i.e. with a defined ridge on each side where the body increases in size, and the body is more red than brown. They all have markings that say "MNT".
Accompanying this batch was two small slips, one labeled "B.H. Component Factors Ltd" which says "Due to resistor shortages Internationally, this kit is from 22 ohms - 2M2", and the other one says "Due to a change in manufacturing methods, this kit may contain new-style metal films, which are colour coded. These will replace the red "letter coded" types, and are being supplied temporarily at the old price. New higher prices will apply from April 1st, 1974".
So what exactly have I got here? Are these resistors any good? All of mine are letter marked, so presumably not metal film. If they are carbon film from the early 70s, they might still be really nice resistors for vintage style builds, I guess?
JTM45 RS OT, JTM45 BB type I, JTM45/100, JTM100 black flag, JMP50 1986, JMP50 1987, JMP100 12xxx, AC30, BFSR, Boogie Mk 1, Hiwatt JPP100, CP103, DR103