"70ss" is a road (ss) bottom bracket spindle for an Italian (70) bottom bracket. Not sure why your frame has this in there. A Paramount should be English, and a 68p (pista) for a track frame.

Not a Paramount, unless the BB threads were screwed and it's been retapped. In that case you should have had a 2mm spacer inside the fixed cup.

In any case, if you are reusing the cages, toss them.

Edited out until measurements: Alright, since the larger balls don't seem to be working - this may be what has happened. The shell was retapped Italian, but for some reason a 2mm spacer was not installed. This caused the adjustable cup to sit way out, so to "fix" this smaller bearings were installed. Get thee a bag of 25 'grade 25' 1/4" ball bearings and a 2mm spacer - and you're set. To help confirm this diagnosis, measure the width of the shell. If I'm on the right track it should measure 68mm

Continuing edit: see the next two posts. You may have an SR titanium BB w/replacement steel spindle with the orig small balls. But that mixed variety may not work well, as you're finding out.