Wandel & Golterman SPM-30 Selective Level Meter
This Selective Level Meter was purchased by the Electronics Section in the mid 1980's and as far I recall was only used once by us and once by the Telecoms department..I think they bought their own after using this one.
I believe the meter has been in storage and not used all this time. It still has the original batteries which as you can see need to be replaced due to leakage but considering they've been in there for 40 years not much damage has been done.
A little restoration of the SPM-30 is needed, cleaned, new batteries (possibly not neaded) and then tested to see if it still works!
On the back it is labelled 'Made in the United Kingdom by Hatfield Industries Ltd'. After a little research I came across this thread on the UK Vintage Radio forum which gives some interesting background on the company.