That is a great set!
The metal and glass tubes aren't any more dangerous in my opinion, maybe less so since there is that much less glass, they are also remarkably light compared to the glass tubes.
You will need to R&R the tube to check on your progress although you can power the chassis up without the CRT and check for high voltage and B+
I would recommend finding a "Test" CRT like this one:
http://www.audiokarma.org/forums//at...=&postid=19731
8XP4 I think they are or 8YP4, can't remember which one is the large neck tube. They show up on eBay all the time.
It's much easier to handle and can be left in place while you work on the set and if you break it no big loss as long as you don't get hit by flying glass
The metal tubes are awful to work around because the entire metal cone is charged with high voltage, it's almost impossible NOT to get shocked if you work on it with that tube in place.
Eric