IMHO, I'd definitely give the diaphragm carb the benefit of the doubt! I have an old Craftsman leaf sweeper with a Tecumseh H35 on it with a diaphragm carb and it still runs like a top. The second reason is I don't believe there is a cheap alternative, at least that I can find. The parts list for your specific model unfortunately doesn't list the part number for item 240, the bowl carb, but a little digging uncovered that the part number is 631444. That has been superceded by 631800A. Unfortunately, I didn't find any cheap import alternatives for it. Much less expensive to put time into getting the one you have cleaned up and running and hopefully you don't run into the problem upupandaway had. [there are cheap alternatives for H60 engines(I know you have a V60) but they all have a choke arm and shaft. If you are really dead set on it, the choke could be removed and the shaft hole plugged with JB Weld. Put the effort into what you have first!]
Keep in mind too that in addition to the fuel side of the engine, the ignition side may need attention. I know you intend to put a new plug in it but the points and condenser may need adjusted or replaced. The condenser is an electrolytic capacitor and they dry out over time and change value and the points of course get burned. My recommendation is to try and start it and only pull the flywheel if you have to. If you do end up pulling it, I'd go ahead and replace the points and condenser since you will have put the work into getting at them in the first place and the good news is they aren't that expensive to replace! If you end up down this road, also consider replacing the flywheel key. It's a cheap part but can cause hard starting and poor running if it's sheared in the slightest. Even if the amount of 'shear' is small, that little change in timing can wreak havoc!