And, on a somewhat related note, I did actually more or less finish ONE of the carbs that's going on my MG while the originals go off for rehab.
Most of what I did was cosmetic(they were pretty grungy) but what prompted me to dive into doing a pseudo-rebuild was a leaky gasket at the base of the float bowl where the jet connects. I actually don't have that fixed yet-I'm still trying to get the old gasket out. I did do new needles, seats, and floats along with several other gaskets. I also "blinged up" the dash pot dome.
Also, take note of the throttle disk. The rehabbed one has a solid disk, while the other has a poppet valve in the disk. The poppet valves are an emissions control device that keeps the mixture from going rich when the throttle is snapped shut.
Unfortunately, the springs lose tension and the valves start to leak all the time.
Many folks will solder them closed, but that doesn't fix one of the other major issues-you still have the valve stem and spring right in the air path.
So, all said and done, installing solid throttle disks is most certainly a sound decision IMO.
Also, at the top end, the engine is SEVERELY restricted in its ability to breath. Changing the cam along with a port and polish(these are old sand cast heads-they actually have a lot casting flash and imperfections that can can be smoothed out to make a real difference) certainly helps this, but intuitively I suspect that removing a big obstruction in the air intake will as well. I've not seen published figures, but I suspect that ditching the poppet valves may be good for 1-2HP-not much but every little bit helps on an engine with this little power.