It's plain from your photos that this is not a Purdey (Beesley patent) action. It would be hard to believe Purdey would tool up to make another action to sell to A&N.

Here's a Purdey action. Look carefully at the pin placement, and you will see it is completely different from your gun.

The Purdey (Beesley) action is a self-opener. That means it springs open when you operate the top lever. There are levers rising through the water table on each bar just behind the hinge. These serve two purposes: they cock the tumblers by way of rods through the bars, and they transfer the spring tension for self-opening the action. Here's a view:

You will also notice the lack of A&D cocking levers protruding through the front of the bars. Your gun clearly has A&D cocking levers.

Here's a view of the front of the hinge:

When you consider these significant differences, you will agree with me that this gun was not made by Purdey.

Curl