Bill, I have done that exact job in Azusa alloy wheels, 15mm off centre was enough for me. No problem at all. Countersink slightly to take off any sharp edges.
Probably fill the old holes/half holes with epoxy if you can, araldite, whatever you have.
Moving the hole for the tube valve made the world of difference, Valve finally sits properly, and adding air is no as easy as it's supposed to be.
I say DO IT!
The general problem seems to be that the TR87 style 90 degree valve tubes do not have the valve in the centre, it's offset. Originally, I did originally start with centred 90 deg vlave tubes, but every one bought since then - same brand, same tube - was offset.
It's a far better solution I think to modify the wheel to take the normally available anywhere TR87 tubes.