RP100 Potentiometers

Ok. So I bought this RP100 off eBay. It is a 1979 chassis from a 112 put in 100RP head box. I’m assuming that it is a GP2 mother board. I’m working through it systematically. I had the bias checked. I’ve put new JJ 6CA7 tunes in and 7 new LM1458 op amps. It is starting to sound decent. I cleaned the pots but some sound pretty worn out. I’m replacing the gain potentiometer which is a 1M audio taper which I’ve ordered from Mojotone. The volume pot is a 10K Linear taper according to the schematic. Mojotone only has 10K audio taper pots. Thinking about it, I thought that audio taper was the best option for volume pots. I’m of the school of keeping amps to factory specs but this is a bit odd. Does anyone know the reason for using a linear taper? Anybody know of a source for these?
Ewan