rather than sq rivets I would just use two per crossing and off set them---a lot easier than messing with sq rivets. (eg one in the top left quadrant of the crossing and another in the bottom right quadrant)
Lets see Aluminum metal is hardness 2-2.9 on the Mohs scale and Aluminum Oxide is hardness 9 (diamond is 10) Iron oxide as scale has done a dandy job of polishing and smoothing the faces of my hammers and anvils Seems like you have things mixed up somewhere Note that if you have ever seen someone take an Al can to scrape ice off their windshield and see them scratch it you might not sal Aluminum Oxide is too soft.
They don't make parts for these anymore; several of my old ones have had new paddles brazed on; one was riveted on. You are on your own unless you can find a "donor" and even then transfers can be tragic.
generally the cost of repairing a screw/screwbox on a vise is several times greater than getting a vice with a good screw/screwbox. If you are good and well equipped for welding or machining and do not count your time as having a cost and can get the vise at scrap rate then it might make sense to get one for repair.
It's rather like buying a car where they say "it's in great condition; only the engine and transmission are blown!"
if you need to do it by hand and do not have access to a beader may I commend to your attention armourarchive.org as rolling edges on things like arm armour does come up from time to time. Do mention your intended use and don't mention "Blankenshield" (an abrasive fellow who advocated rolling *ALL* edges all the time...even against the documented proof of places they were not used)
What does the bottom of the anvil look like? The 1728 is the serial number and if it's on the right and the weight is on the left when looking at it from the horn end then we can probably give you the maker anyway. American made! Trenton with the weight on the left and serial on the right and if I recall correctly that low number would be around 1898; so not an old anvil; but a great one!