Browning A-5 12-gauge Shotgun

Question
I have a late 50's/early 60's Belgium A-5 Browning 12-gauge.  Lately it does not eject spent shells cleanly.  My father put an "all in one" poly choke on it upon purchase.  The forearm wood is cracked, but does not affect operation of the gun.  I want to rehab the gun without doing damage to its value.  What can I do/not do toward this objective?

Answer
Many things could cause the ejection problem.
First take it down and clean and lubricate it.
If the problem still goes on bring it to local gunsmith.
It should be easily repaired.
A expert gunsmith can repair the crack most likily as well.
If it was was an after market poly-choke as opposed from the factory, it collectors value is gone as its not orginal. Its worth $400 to $600.
Repairs will not damage that.
Its highest value is as a family heirloom.