Thank you for your comments guys.
Jpmcwjr, I found them in the storage room of an old tobacconist where my father used to get his baccy. I paid, roughly, USD 13 each.
Jackswilling, I didn't know these knives were still being made. Cool! On the other hand I've never seen a new one in Argentina, where I live. Only antique ones.
Tyler, ChasingEmbers, looks like AAD is very real!
The Richards knives are no longer made as the company went into liquidation in the early '80's (I think). They were not the highest quality knives to come out of Sheffield as they were mass produced but very serviceable non the less. The knife shown in Jackswilling's post is a Joseph Rodgers knife which are regarded as one of the best knife-makers in England. These are/were available with wood and horn handles and very nice they are too, although these too are probably now stamped out in the Far East.
One of the best, but rarely seen, pipe knives is the Wilkinson Sword knife. These were made to a much higher standard than either the Richards or the Rodgers knives although the scales were not as good as the Rodgers horn scales (Buffalo Horn I believe).
Ironically, Richards was founded by two German brothers (Richartz) in the 1930's and the factory was very badly damaged by bombing during the Second World War. They did, however, go on to become one of the largest cutlers in the UK.
I love those little devils, pipe tools in the pocket knife configuration. However, I am so impressed with, and devoted to the pure simplicity of the pipe nail and horseshoe nail as two ended pipe tools that handily serve as tamper, scoop and to some degree pick, that that is mostly what I use. I have the usual Czech tools, and am forever tempted by these pocket knife like tools, but to have it all in one small tool, for 92 cents, and pleasingly designed as well -- I have never been able to overcome that pleasant device. That said, I have a real weakness for pocket knives. I try hard not to collect them, but I accumulate them anyway.