Just checked with a guitar nerd (member of a guitar forum) for you Ralphie - LGOs still available, so value depends on age and condition and history, does it have the original case etc ..
Is it pre-War? They made good guitars (worth a lot in which case) .. '70s onwards not good.. (I'm just quoting this!)

As you are in London .. take it down to "Tin Pan Alley" specifically to Hanks in Denmark Street, as it's staffed by enthusiasts they are quite likely to answer queries .. otherwise the Acoustic Centre (not in Denmark Street - you should be able to get the address through Enquiries)