The Humber 1 ton uses the RR B Range engine and all of these whether in 4, 6 or 8 cylinder guise use the same Lucas screened distributor. Only the rotor arm for governed service, caps for 4/8 or 6 cyl use, and the cam as a 4 or 3 lobe item changes from one engine to the other. All the point sets are the same and not handed.

The B60 engine in the Humber 1 ton is the same (some external ancillary differences) as the Humber Pig and Ferret. The point sets are available from Marcus Glenn http://www.marcusglenn.com/

I have some if you're really stuck but I had to buy them too and a depletion of what I have may well make my mind up to do a Jolley Eng electronic conversion.

Note the 6 cyl twin point configuration of the Lucas distributor is in effect two 3 cyl ignition systens running on a common 3 lobe cam. It is essential both sets are correctly timed 180º apart at the distributor and therefore 360º at the engine by using the marks for No.1 and No.6 cyls respectively. However you will find the movement of the adjustable set also alters the gapping and a few thou here makes a huge difference to the relative sync angle.

Its a bit of a fiddle I'm afraid.

Do not attempt dynamic timing with a strobe as the mechanical advance is intentionally operative on or about idle and your settings will be very wrong.

R.