Stock? I personally think the lead channel would be in the ballpark, but I think a Purple would be a little less aggressive than Sykes tone.
If you’re trying to nail Sykes tone, you’d be better served using a Blue Stripe like he did, but you could pick up a Black/Purple/Red/Blue Stripe and have Mesa mod the Lead Channel to whichever revision you’d like. IIRC, it’s only a single cap, and these amps may benefit from a factory refresh (although my IIIs are still running strong).
The only reason I didn’t recommend the Green Stripe is because the Greens run in Pentode, whereas all the other Stripes run in Triode. Pentode is more “authoritative” or forward, while the Triode sounds sweeter. If you have a Mark IV, you can try changing this setting and see which you prefer best.
i always thought he used a black stripe/no stripe - at least on the WS recordings, since those were done 85-86?