Dear Roger: This is a critical subject ( posted by Rushton ) on what you ask:
+++++ " The 45 rpm disc, all else being equal, moves " ++++
If you ask because you want to buy 45 versions of " today " good 33 ones please do it with care: many ( I can say several ) of those 45 versions are inferior ( quality performance ) over the 33 same ones. Not every thing that " shine " is gold.
Regards and enjoy the music.
Raul.