I found uncletom's experiments a bit confusing... He placed the convergence rings on tubes that don't need them?
The Philips tube has a yoke that has a built in ring set on it. It's a 2 in 1 unit. If you're going to put any other yoke on it that normally has a separate ring set you will have to include too.
You can try it without one. It's going to look wonky as hell.
Problem is that this Philips TV produces a great image, and I'm sure that if I remove the yoke I won't be able to set it as good as before.
There's like zero adjustments done with Philips yokes. You literally place it on and make sure it's correctly oriented (as opposed to rotated). Check the first two posts in this thread. Just be careful when removing the yoke. I've heard that the windings can come off.
The Philips isn't a perfect match with the 293X. The mounting ears are at the wrong depth and the curvature isn't quite the same. Again, if I had no tube, then yeah, it's worth trying. Otherwise no.
Sony I wouldn't even bother with.
Daewoo, no idea.
The Shanghai Novel tubes in 29e31s are indeed the correct curvature. You will only find one in an arcade cab though. 29e31s is also 31khz only, so again something you would have to yoke swap or put a Wei-Ya chassis on. Be advised though, they are extremely poor tubes. I have 3 that have either dead or dying electron guns.