[Kenwood] Replacement Dual Pot for Kenwood TR-751E

[Keith & Jenny Sloan]

I need to replace the dual concentric pot that controls 
AF/Squelch/On-Off. I have tried Kenwood UK/Europe/USA
and have been told the Kenwood Part number is R23-9402-05 but not available.
Back in January Acoustic told me they could obtain the part as it was 
still a valid Kenwood Part,
but might take some time as there were non available at the factory in 
Japan,
but recently they informed that the part had been withdrawn and was now 
obsolete.

I am trying to get an equivalent part from www.potentiometer.com who 
make custom pots, but I am unsure
of the details of the Kenwood Part. The circuit diagram in the manual 
lists the pots as Volume : Variable 10K (K)
and Squelch : Variable 50K ( B ).

Can somebody confirm what the (K) and (B) mean? I assume some sort of 
curve probably log.
www.potentiometer.com list various curves in their PDF spec but I am not 
sure how to marry the two.

Also if anybody knows where I can get the specification of the Kenwood 
R23-9402-05 in terms of sizes, pin out etc
that would be great.

Thanks Keith
M3VBN