2Sk100 , 2SK170-V, Yamaha C4

Hello,
I need to replace a 2SK100. A pair reside in a Yamaha C4 preamp and one appears to be playing up.
It’s a ‘dual jfet’ and one suggestion has been to thermally couple a well-matched pair of 2SK170-V.
Any advice gratefully accepted with regards to the suitability of this solution, better alternatives or, indeed, where best to try and procure genuine stock of 2SK170-V.
Many thanks.