[Parker-Hawes]

Hello All, I need suggestions on how to remove the forend on the gun I mentioned above. Anty ideas ?The forend seems to really be stuck ! Is it just hard to move because the spring is extra strong on the big Trap forend ? Has it just gotten stuck because of non regular routine cleaning over the years. It appears to a factory model by looks. I of course want to see the lug underneath and water table and all that stuff. Thanks in advance Best,Paul