Hello Brian,

Welcome to this forum full of good old radio stuff.
The following web page shows the original manual and has all the details you might need.
But.... it may be double dutch to you

https://nvhrbiblio.nl/schema/Philips_2511.pdf

The drawings are usually very helpful and, hopefully, Google Translate is too.
Maye there once was a Mullard equivalent of this set with service docs in English but I don't really expect that considering the year of make.
Bear in mind that Philips often made changes to the sets during production without immediately releasing document updates and sometimes they never even bothered at all!

If Google and the drawings still leave you puzzled, feel free to contact me.
I have no practical experience with this particular model but might be able to do some translating for you.

Good luck with this wonderful set.

Kind regards,

Henk

PS: you can contact me by clicking on the little envelope behind my name