When out in the garage, I like to think I live by the "do it right or do it twice" motto. Strive as I might to be that person, the reality is that I'm cheap and will always try the easy route first. And second. On the third go-around I might do it properly.
This strategy bit me in the butt recently as I went to repair the exhaust on my 1930 Ford Model A.
Watch the video over on Hagerty.com: https://www.hagerty.com/media/videos/model-a-exhaust-fix-adventure-detours-ahead-kyles-garage-ep10/
Kyle - you showed the holes in what might be loosely termed the firewall of your model A. Amazon has a collection of rubber grommets for $11. A bit over 1/3 of these are solid rubber and would work well to fill those holes. The manufacturer is Ram-pro and the EAN is 0815518023904.
I get this all of the time: "I don't want to spend a lot of money..."; "I just want to get my car going..."; "I'll do a better job down the road..."--and complaining because the car won't run right--AGAIN! I ask: "How many times do you want to be broken down at the side of the road before you do it right?" I always get that hang-head response.