In one of the links at Classic Lightweights, you will see the email address of David Hull, the V-CC Marque Enthusiast. I would recommend that you contact David.
I see you have posted on
CycleChat and getting come information.
More threads are worth reading through on
CycleChat
If it is a linear frame numbering system it MAY have been built close to
this one with a frame number of 6281
RetroBike has
a number of threads including one likely to be from David Hull where he
asks for frame numbers.
Also
LFGSS has a number of threads on Rory O'Brien that also should be read.
And any of your mate's family able to recall any history of the bike?
I make up a spreadsheet with all the components for the bikes listed, and preferred components with links. It depends where you are as to the best source of components, so get the build year as soon as you can.
This should keep you occupied for a while, and able to comply with the social isolation in a productive manner.
Come back and keep this thread updated.
A search on the
FB group Vintage BicycleUK has a few posts, and it is a possible source if you need further information.
Once you determine the date of the frame, then there are a number of resources I use to consider period parts. Firstly look at
Classic Lightweights Readers bikes for those with the same build date. Use Hugo's Component Database to filter and sort.
Then you could go
Three Speed Hub and look up the Holdsworth Aids catalogues to see what was being sold in the that period. Also look for other marque catalogues of the time.
Speedbicycles is also well worth looking at as you can see some wonderful photos of period bikes, well lit and well-focused. Again focus on your frame year.
If you
join the V-CC you can get access to their extraordinary online library to see what components were fitted to bikes of the same period.
Get the frame assessed to see if the frame has been structurally weakened by the rust, and if there is any rust damage inside the tubes. Then we can suggest where you can get the components.