Gooser,
I would simply order a small assortment of the blued steel 'Blanking screws' from Brownells or buy them from your local gunsmith, if he has them in stock. Then install them and go about enjoying your new acquisition. You have what is a diminishing return conundrum, meaning that it is not going to be cost effective to worry with welding and refinishing from a return perspective. There is also the worry about who is going to do the work and how they will polish the receiver and treat its original edges, &c. in the process of doing the refinish .. it could very easily end up worse than it is now, much worse. A proper fit blanking screw [some are counter sunk, some slightly proud; some heads are flat, some convex] is not all that unattractive and if you want to use a scope at some point you would easily have that option still at hand. Lastly, there is the possibilty that the other holes on the side [and possibly the top as well] were for a receiver sight and not another scope mount. Typical progression being OEM open iron sights to receiver sight to scope. Just some thots.
I'll go out on a limb & say that it will retain its value better w/blanking screws than welded up & reblued. The moment its finish is non original any collector value just went south.
They are neat .22's that beg use.
