A common problem with some Parkers is that the bbls won't come off the frame after you take the forend off and then open the action.
The issue is related to the 'hook' and wether it is releasing from the cocking arm.
But rather than getting into all that, you just want to inspect the gun with the bbls off the frame,,
An easy way to dismount these that don't want to dismount is to simply dryfire one bbl
or both, doesn't matter,,after removing the forend.
Then open the gun as normal and chances are 95% of the time the bbls will come right off of the frame.
The bbls can go right back on even though the hammer (or even both of them) have been dry fired.
The forend of a non-ejector gun will slip right back in position.
Open and then close the gun and it is cocked once again.
If the gun is an Ejector gun,, the ejector(s) will be 'fired' after you dry fire either or both bbls and then remove the forend.
To put that forend back on it's easiest to re-cock the ejector hammer or hammers first.
Take the forend in one hand with the ejector hammers facing back at you.
Place the end of a piece of wood against the face of the fired ejector hammer(s) and push them back till they 'cock'
I usually just use the end of my bench hammer handle,,works just as well.
The V springs powering the ejectors are quite stout, so it takes some effort to push them back to the cocked position. You can do one at a time or both together.
Once the ejectors are cocked, the forend goes right back on the gun even though the hammers are down/fired w/ no problem.
Then open and then close the gun and the hammers will be cocked as well.
Another way to recock the guns hammer(s) alone w/o the bbls and forend being on the frame is to reach into the firing pin hole in the face of the frame and push the hammer(s) back to the cocked
You do this with a shop made tool.
Simple, made from an 1100 fireing pin (an 870 works too I think).
Cup the tip of the pin with a small center drill.
Then mount tool in a small handle..that's it.
To use, the tool is placed on the tip of the exposed firing pin of the fired hammer. The cupped point of the tool fits nicely on the tip of the FP.
Then simply push the hammer back to the cocked position by pushing the tool inside the frame.
No, it won't slide off of the tip of the FP or damage anything.
Handy for working on the hammers/sears & recocking the hammers you don't have to constantly have to put the bbls and forend back in place.