This article from a 1965 Look & Learn magazine shows some interesting photos of some behind the scenes shots at the A.P.Film studio in Slough.
The article deals principally with the unique lip- sync technique, and technical issues about the shows.
I love this shot which shows the team at work. Note, what appears to be a model road or landing strip just next to the puppet set.
This shot looks like puppeteer and sculptor, John Blundall putting the finishing touches to a puppet head.
A shot of the A.P.Films workshop.
The miniature prop store.
Oddly, there's no mention of Gerry Anderson, or indeed any of the staff, although the puppet characters do get a name check.
The same issue also featured this article on a proposed prototype Subplane which wouldn't have looked out of place in those early A.P.Film productions.