Cartridge allignment Especially VTA

I found my plastic Denneses Soundtractor. The Arm Part is Fine, but the Spindle part with the allignment marks is pretty warped.
I tried to flatten it with a heat gun with some success and was going to try it today when I got home.
Then I remembered that the RB900 that I have has no clear pivot point on the top of it. I guess the soundtractor is useless.

I have a wolly tractor for that arm but I don't really trust it - it looks very Micky Mouse.

Worse than that - I've been playing with VTA Lately with disturbing results.
Where it ended up sounding the best just doesn't look right.
The back part of the arm is slightly lower than what would be parallel to the record. (Benz LO4 and Basis 1400)

Could there be a analytical way to do this?
I have some accurate electronic measuring equipment.
I also have a record with test tones.
If the VTA was perfect - I would think that would result in maximum amplitude. I'm not sure if there would be enough amplitude difference to notice if it was slightly off.

Also - just a note here.
Maybe VTA can be adjusted by tracking force.
My theory is that as long as you are tracking heavy enough to properly track the groove - any additional force would really just affect the VTA.
(assuming you always remain in the manufacturers tracking force recommendations)
But possibly tracking at a different force will put the cartridge works in a different spot - thus changing the sound in yet another way...

Any opinions or comments??
Should I just find something to smoke and just shut up??