You've already got it prepped for TIG, so why on earth would you want to blow stick welding slag all over it, and suck in nasty fumes?

I'd set a #7 or #8 gas lens, 3/32" tungsten, amps set to "kill" (250 amps) on the footpedal, and have at it with E70S2 or S6.

Weld in stitches to keep cool, and try to make it look like a perfectly welded, oxide-free stainless steel weld, for fun. Visually observe back side of weld to verify complete penetration.