To drop the slew rate of the TL070 from 13v/us down to the 0.1v/us of the LM308 requires overcompensation.
There is nothing sacred about 0.1v/us, BTW.
If 18pf yields 13v/us in a TL070, then 180pf slows you down to ~ 1v/us, assuming the charging current mirror doesn't saturate (which it probably will if you go for 0.1v/us)
Start there and work down to what sounds good to your ears.
This is about LISTENING and using your own artistic skills.
FWIW... and oh, YMMV.