it is possible that the same machine was imported by other suppliers under a different name / number.
i.e the Rong Fu RF 20 and RF 25 were imported to UK by more than one supplier,
PCD 30 suggest that it might be something akin to a RF 30 which was possibly known in UK as a "Major" or some similar name.
Any other number available from the data plate, such as manufacturer? Even spindle speeds, and belt positions, may help.
Pictures would help.
So it may be possible that an Operator Manual for one importer's machine may well be what you are seeking.
If you can run the machine to earth, a manual or a photocopy might be made available to you by someone on here..
Howard