Thanks Julian,
Thanks for that extract  - very bit of info helps. Even jacking the bike up is not entirely straight forward - it is so low to the ground that neither a bottle jack or trolley jack will fit under.  I presume it is not advisable to jack via the crankcase, so I need to sort out a way to lift it only by the lower frame rails, which are only 12 cm or so from the ground.
Cheers,
Bevan

Hi folks,
I'm new to girder fork bikes and would appreciate any tips on swapping the fork spring on my 1929 Sloper.  I presume it is under compression. Have bought a new spring since current one is very soft.
Cheers,
Bevan