Just curious about this. The parts books from 1932 and 1934 both show the right hand footrest for a W34-9 to be 15-8167 (forged part) and the left to be 15-8158 (fabricated flat bar). My machine had been incorrectly fitted with two forged footrests and I've now just got round to makeing the correct one for the left hand side. However, although both of the forged footrests fit the right hand side correctly, when I've looked a bit more closely I see they are stamped 15-8168 - which doesn't seem to correspond to anything fitted to a pre-war machine. I'm not bothered by this as both seem to be the same spec as 15-8167, but it's very odd that the part number is one digit higher than it ought to be.
David
Interestingly, I note that footrests previously sold by British Only Austria also appear to be marked 15-8168 - see attached, that last digit definitely not a 7.