Many will drill the lock if they have issues opening. That will not, of course, fix a broken mechanism. FYI- new lock cores are cheap and widely available.

I believe you are correct and that gorgar has a mech that basically is a long metal bar that rotates over the backglass with the key turn. Others that own this game can confirm- I am going with what I see on my games of similar era.

Good luck. Go SLOW. Its your first game and you will be much happier when things resolve without needing repair.

Wanted to add- do not indiscriminately spray lubricant into the side. The backglass will get hit and can be permanently damaged!!!

You can lubricate but gently if there is such a thing.

A lot of times, if the lock mechanism is working (and if there is a difference between how much you can move the glass when it is locked or not), the top channel on the glass has come loose and is jamming things up. When you look at the glass, you will see the lift channel at the bottom, and then side channels, and a top channel. These basically clip over the edge of the glass. Have a really close look at them all, especially at the top.

at around 6:30 toddtuckey removes this glass (but didn't have any trouble with the lock )

I have had this same issue a couple of times. Here is what you do:

First: be incredibly gentle. This should go without saying, but seriously...be careful.

Second: press gently on the glass and move it upwards in the side that isn't going up as much. Try this on the top area first, and then on the sides.

Third: scoot the back glass over to the side as much as possible and then gently lift it up.

It likely isn't the lock or bar. It is most likely the trim that isn't fitting well, tape that was added improperly, or the wrong size/type of trim. You just have to figure out how to jiggle it and get it loose.
Drilling it or using a lubricant probably won't help at all.

First tip. It’s not a table. It’s a pinball machine

Coincedentally, I ran into a GorGar with the same problem once. The screw that attached latch bar to the lock barrel was loose (Found this after I got the glass loose).
If you can get a thin piece of stiff wire (say like a piano wire), put a short 90 degree bend on the end of it about a 1/4" long.
Unplug the game.
With a flashlight, point the light through the grill at the top back of the back box on the lock side. Gently feed the hooked end of the wire until it reaches the underside of the latch assembly (Not the bar that come off the lock barrel.
Latch Bar (resized).jpg

You want to get the bar that runs under the top of the back box interior). Be careful to not go to far forward and hit any wiring or the back of the back glass. Hook the bar and gently pull it back. The back glass should lift out. If the bar doesn't move or move far enough don't try to force it. It's not worth injuring yourself or damaging the game.

Please keep us posted