Time to rebuild?

The rebuild won't happen until summer anyway, so I have time to try a few things first. Regarding the float needle: I assume if it were gone, the engine would be completely flooded and not running, but is it possible that somehow the carb bowl could be overflowing occasionally? On a possibly unrelated note, my idle mixture screw has a plastic cap that prevents it from turning more than a half turn. Does that mean I shouldn't need to adjust it?

One thing is for sure: the engine runs reasonably well, although I've noticed just in the last few weeks that it starts right up but then after a few seconds starts to bog down and doesn't idle well until it gets warm. Once warm it's fine. Then again, I don't have a lot to compare it to. Maybe after rebuild I'll be laying down rubber at every intersection, ha ha.

The PCV valve is correct: it's stamped 2103 and is the one listed for a 1974 225. I'm still holding out hope that my valve cover baffle is simply clogged with crud, preventing good ventilation. It is very caked with black crud. I'll see where I stand after cleaning that out, adjusting valve lash, and running the fuel cleaner treatment. Just in case gunk is interfering with the valves, maybe I'll run the fuel treatment through before opening up the valve cover.