What do you mean, Paul, "running out of space"? You've got several other rooms, haven't you? I have to contain my Avo collection within a modest 10' by 10' shed...
I hope this is the right place for my question, which relates to the different styles of battery cover fitted to Universal Avometers with top access to the batteries. I have come across three cover types, and as these seem to be interchangeable (and probably get swapped around by previous owners) I wonder if specific types of battery cover were fitted to specific Models of Avometer, or whether the pattern simply changed over the years?
1) Bakelite with narrow slot and fixed 'overbridge' marked "PRODS" under which a pair of prods can be slid and retained
2) Bakelite with two slots and a rotating clip, to secure a pair of prods plus another probe of unknown type
3) Flat metal plate, finished to match the case
I'm tempted to think that cover type (1) is the early pattern, as I have an original Model 7 from 1947 with one like this. Type (2) could be a later pattern, as it is shown fitted to both Model 7 Mk II and Model 8 in images dated 1957 and 1960. Type (3) turns up on various Models.
Could it be that the flat metal battery cover was supplied as standard, and Bakelite battery covers were optional extras at additional cost?