I recently purchased what appears to be a little used BL-22

I got on UTube to view the dis-assembly videos and fully understand the process.

The problem lies with getting the pieces apart. After I remove the screw from the side of the receiver the internal parts of the receiver and buttstock assembly will not separate from the outer receiver "shell"

Tugging doesn't help. Wrapping the receiver in a towel and lightly tapping with a rubber mallet doesn't help.

Before I go any further, I wanted to see if any of the BL-22 fans might have experiences with this rifle that can guide me.

Appreciate any help that can be offered