John, my tailstock was out of alignment which I then set correctly. Making cuts now with the cross slide only, does not induce taper. I've resorted to making finishing cuts exactly like you describing without any noticeable taper but poor finish.
I'll work on my speeds and grinding of cutting tools shortly. I just wrongly assumed that for better finish you must use the top slide. And it did.
Bernd, yes you're correct on all counts. Sorry for causing confusion. I'm using the Boxford manual and it defines it's compound as having a compound slide (swivelly bit), top/tool slide (back and forth thingy) and a toolpost. All that is on the cross slide.
But we're on the same page.
For parallelism, I salvaged the carriage shaft of an old dot matrix printer which in my mind should be pretty accurate. So I just remove the toolpost and put the indicator in its place and adjust accordingly?
I'll get a machinist's protractor which should be more accurate than the one I'm using.