You can arc weld cast iron with lots of preheat, nickel rod and bondo if you want it to look good but where strength is important the bond is always questionable. I got my General 20" band saw cheap at auction mainly because a chunk was broken out of the corner of the table. Someone must have tipped it over with a fork lift in a move sometime. I fabricated a piece of steel to match the gap in the corner of the table. I didn't use any preheat so I spot welded the steel in the gap, in a stitching fashion to prevent to much heat build up and possibly cracking. It is quite strong enough for its purpose but I wouldn't trust it under heavy stress. It didn't look pretty but the bondo cleans it up ok. That was a couple of years ago and I still haven't got around to painting it yet, ha ha.
The broken chunk cut across the middle of the fence mounting hole, to a little more than a 1/4" from the top and extended around the corner.
So back to the vise, the angle scale was surprisingly in perfect shape, after cleaning up. Here all assembled and set to 90* cuts.
Here 11 1/4" between jaws at full capacity.
Here with 3" square tubing clamped between the jaws.