Just bought, sight unseen, an Ideal grade 16 gauge, serial #67805, mfg in 1913. Condition is better than I expected: checkering unblemished, bores bright, action tight. However, cannot determine how to remove the forearm. There is a hole at the top end, which a friend/collector suspects had a push-button forearm release. Dealer says just put finger between barrels and forearm and pry. Any advise?