I have morris classic in my 68. Only thing annoying is you do have to reach far back to grab the belt. Sometimes when pulling the belt it locks and I have to stop to get it to unlock.
But, I would definitely buy them again.
I had my 71 belts rewebbed by Sharons Web.
http://www.sharonswebinc.com/
The stock 71 belts, with the shoulder harness locks you into the car much better than belts with a retractor