Polyvaricon tuning cap advice needed

[Quantumplate]

Hi folks, i'm going through an 80s boombox - the Goldstar tsr 800 - repairing its many faults. I have an odd tuning dial indicator that won't move over the lower third of the dial. I've extracted the pcb chassis and can now manually rotate the wheel attached to the varicon. It rotates to the high frequencies (108) and hits the buffers with a definite stop. At around 93Mhz it grinds to a halt in a rather spongy way, like there should be more travel to go. The stringing appears to be fine with no restrictions. The max angle of rotation of the shaft between its current limits is about 120 degrees. I have another varicon lying around, different brand, that rotates 180 deg. So two questions: is 180 standard? And could i expand the rotational limit/capacitance by messing with the trimmer screws?
Thanks

[wasedadoc]

Yes, 180 degress is normal. I've never seen one that is not.

No, do not mess with the trimmer screws.

Does it have a transparent housing and can you see the insulation sheets between the moving plates?

[Quantumplate]

Yes, 180 degress is normal. I've never seen one that is not.

No, do not mess with the trimmer screws.

Does it have a transparent housing and can you see the insulation sheets between the moving plates?

Much thanks to you. Yes, 180 makes sense what with two semicircular vanes meshing.

Well it's clear in places. I've just had a really close up look and i think i've found the problem. A great splurge of fawn coloured glue has been laid over many components adjacent to the varicon, and down two of its sides. Incredibly, upon close inspection i can see dozens of fragments of this glue inside the varicon! This is even more interesting to me as i watched a YouTube video demonstrating this boombox once, and it had exactly the same issue with the dial! It even pegged out at the same spot. So it's a factory cock up.

Tempting to try a little force and see if i can grind up the fragments maybe, or bite the bullet and go for a difficult extraction and perhaps open the varicon for repair.

Note: i meant to call it wax as that's what it is. Maybe i can melt it away...