No specific help here, but I have seen those spots in the casting before that weren't used- probably for another spec. If there isn't a hole there or signs of plug marks on the sides- I would try it w/out.

Rebuild kit is on order, will let you know how it turns out.

Hard to say when previous owner has tampered with the Welch Plug Dude . I have silicon-ed or locktited over this area when I have had to due to necessity . Once you receive the Rebuild Kit you should be fine . Ensure to clean all the fuel circuit with concentrated carb cleaner , use a duster or compressed air to assist . Good Luck and let us know your outcome Bro !