I don't own a cast iron ASO, and I never will. But occasionally some poor guy comes along who didn't know any better, and wants to know if there's any way to make his ASO functional. And for a while know I've been wondering: is there some reason you couldn't furnace brace a steel face onto one of those things? You'd have to leave it unhardened, I think (though I wonder if you could get away with flame hardening it), but it'd still be a big improvement.

I know...lipstick on a pig.

I had an aso given to me and what I did was weld a piece of AR plate about 3/8" thick. Now the key to get this plate to stick is useing a high nickel rod, also you need to drill several holes in your plate so you can plug weld the plate to the anvil in order to draw it up tight. Then all you do is weld a little overlay rod on your plug welds and presto you have a very good useable anvil. My 8 year old son uses this anvil for everything including a little smithing and it has held up great and he even has almost taken out an eye from missing his work piece and striking the anvil, it bounced back and got him right in his safty glasses. So I guess if there is a will there is a way.

Sure, that's one way. The knock against welding around the edge has always seemed to be that it's likely to leave a tiny gap in there between the CI and the steel face, which would hurt rebound and wouldn't be as strong as a bond across the entire face. (It doesn't sound like that been a problem with yours.) The thing about brazing is that ideally it'd allow a bond across the entire area of both surfaces, with no gaps.

I'd rather build on Grant's modular anvil idea and mill a dovetail into the top that could receive tool steel inserts. The milling would be way less energy intensive ($) than heating the whole thing up to the point where brass would flow.

True, though wood is pretty much free. :)