What kind of sound are you going for?
If you're into vintage wah sounds, I'd suggest either breadboarding the circuit or socketing Q1 so you can experiment. To my ears, (much) lower hFE ranges sounded a lot better. MPSA18 have crazy high hFEs. I ended up with a JAN2N2222 with hFE below 200 on my build.
Breadboarding also helped with choosing the inductor.
Lastly, pay attention to the taper of the pot, it has a pretty drastic effect on the transition between the two extremes of the frequency sweep.