Thread: tighten vices & bench stop

Have 2 wood vices -Patersons patent vice -god knows how old -very methinks and a Dawn No: 9 -at least 60 YO. Both are of the quick -ie. flick the lever and push/ pull to close and then tighten with the handle type. Both slip when tightening. They both have a flat bar underneath that seems to be some kind of torsion spring for the quick change movement. How do you tighten such devices?
The other thing is a bench stop - for planing and such things That was in my granddads old workbench (He hand planed an entire house worth of parquetry floor -all fitted and numbered!!!) The issue with this is RUST -want to avoid damage to this but the screw adjustment appears rusted into place. The screw appears to work a lever that makes the stop rise or fall. Can move the stop up or down a couple of mm with a mallet, however the screw wont budge.
Has been flooded with WD etc. for months -no avail. Do I soak it in something? try the electrolytic things or what???IMG_20200711_174619_2.jpgIMG_20200711_174547.jpgIMG_20200711_174517.jpgIMG_20200711_174527.jpg
Photos are Paterson vice ,Dawn vice , works of the bench stop & top of the bench stop. Exactly how the screw works the lever to rise or fall the stop - I'm not sure as the angle would surely change as it pivots- possibly a radial thing? cant get it to move - so cant really tell?