Eldonian was bought by Jeffiries ages ago, it's just a name. They also do Eldonian bits, trouble is they are not "made" in England they are made in the east then finished in the UK so they can have the made in UK label on them.
The saddles were made in the E.Jeffries factory, not a bad make all things considered. I used to make them.....make of that what you will!
Hawk Event, Harrier and quite a few other makes are actually made in the E. Jeffries factory.
you probably have a very well made and finished saddle. If it's in good order it should have kept its value.