Looks verrrry similar to the `80-`82 vintage Keihins. However, the `79 does not have the limiter cap, on the pilot airbleed adjusting screw. That's a good thing, btw. I've never been a big fan of the later carbs but, that's changing. They tend to do a better job delivering consistent idle-to-1/8 throttle performance, meaning they improved the low-speed atomization...it matters more than you might think. I wouldn't retrofit an earlier model with one of these, the K0-K1 era Keihin carbs are a lot more user-friendly, especially when it comes to parts availability, including some very good repops.
NEVC and Dratv are the go-to resources for carb rebuild parts. Along with the rubber parts, be sure to replace the fuel screen; it's the plastic thingy that looks like it was pulled from a spray gun. The one p.i.t.a. with this era carb is the petcock. It's easier to replace as an assembly. That turned out to be a sign of things to come, didn't it? If your skill set includes drilling & tapping (threading small holes) the packing can be replaced, it's the 4-hole version; the rivets have to be drilled (very carefully) then the holes tapped, for M3 or M4 screws.
Cannibalizing a pz19 for the choke parts is very resourceful, not to mention cheaper than buying NOS pieces, if they're still available.
Sounds like, potentially, a lot of busy work, when you could just source a new carb (repop, or pz19). However, I see most of the original irriditing (that rainbow-ish color) on the outside surfaces. That means the carb body casting is likely in similarly nice, oxidation-free, condition...i.e. eminently rebuildable.