[Arran]

 The 80 and the 5Z3 are not interchangeable, a 5Z3 is like a four pin 5U4, an 80 more like a 5Y3/5Y4. I'm not sure about an 83V but an 83 is a mercury vapor rectifier so no to using one of those. Put a type 80 where a 5Z3 is supposed to go and it will live a short life, put a 5Z3 in place of an 80 and you might burn out the 5 volt winding on the transformer eventually. I don't know why all of the Philco 16/116 set don't use a 5Z3 rectifier, the RCA Victor model 143 did and it only has 8 tubes with push pull #42s in pentode connected class A, not triode connected class A-b (if the 16Bs had it?)
Regards
Arran