190XT Fuel Pump Leaking?

I went and started up the good ol' 1968 190XT (Series 2, I think) today to get some bush hogging done. It hasn't been started since this spring for plowing. I checked oil and all that good stuff, put in a fresh 20 gallons of gasoline. It started up just fine as it normally does, no issues at all. However, I noticed a fuel leak from what appears to be the fuel pump. I found what looks incredibly similar in the service manual (Page 194, see attached), but I believe it's a little different. The manual also says the G-2800 could have a carb, but it looks nothing alike. I will attach two images as well to show the component/leak.

When I first started it, the leak seemed like a lot. The radiator fan was blowing back against it and causing the fuel to spray all over, so it was very hard to decipher where the source was. I decided to at least let the engine warm up completely at idle (2,500 RPMs) before shutting it back off. Once it had run for about 15-20 minutes, I checked again and the leak was much less severe. I could also now tell that it was coming from what looks to be a relief hole in the lower-half (see attached). If I covered the hole, the leak would stop and the engine appeared to run exactly the same. This is where bad ideas happen.

I decided to plug the hole with some putty to get me through the brush hogging, and then I would dismantle it later and repair it properly. I went out bush hogging for over an hour with zero leaks or issues. Then I had a small hiccup in RPMs. It only lasted a couple seconds and went away. A little bit later the engine did more than hiccup and stopped. I shut it all off, turned off the PTO, etc. Restarted the engine and it idled just fine. I put it in gear to drive it back to the house and it died as I let off the clutch.

I am assuming these two are related. I currently have it sitting in the field. The putty is still in place and sealing the leak effectively - which I realize may be the cause of my current issue.

When I first started the engine today, it appeared the leak was from somewhere on the upper half of the fuel pump, but later, after it died down, it was only from this relief hole. Would anyone have any insight as to what the original issue was, why it changed as it warmed up, and why it shut down after over an hour of running hard?

Thanks!

I've been looking into sourcing a new fuel pump and have found several replacements online, but a rebuild kit would be much preferred. Does anyone know of a rebuild kit for these that is still available somewhere? Or perhaps a cheaper electric fuel pump option?

EDIT:

So I walked out to the field and gave the engine oil dipstick a whiff. I would say it has a fuel smell. Guess I'm gonna give it an oil change and unplug my drain hole on the fuel pump.

Side note. I'm not saying it's a bad design, as I would assume there is a purpose behind it... But why does the fuel pump have a direct connection to the crankcase? Is it lubricated with engine oil as well, being a mechanical pump? I am ignorant on this design, but I do understand it's my own ignorance that has led to a bad decision.