My 1974 Raleigh upright steel bar also just gave way where there was a rusting hole in the chrome.
It was on the right side of the stem. Got stuck with a 2 mile walk home. This bar was crashed several times making the right side pushed in. I did lately put it in the vice to fix it some.

So anyway it wasn't laid up long. I went to the co-op and found another perfect bar like new with a couple scratches. I used the CCM grips. It is an inch narrower, so maybe it will be faster. ha And besides that, I got to use a Nitto stem I bought 4 years ago.
Not sure I like using the aluminum though. I grocery bag it a lot of the time.