The Bantam 7 looks to be a single screw jack and if so, it wouldn't be correct for the P type as the parts list refers specifically to a double screw Shelley jack. I think you'l find it's a Shelley A6 you need (and apparently a deep pocket in order to acquire one!)
Now if I could only find out the same information for the J....
EDIT: P.S. But Peter, if you have a nice original style jack it might as well be the one you carry in the car in case of a puncture.
I do have a period double lift jack, similar to, but not a Shelley A6. I tried using it once in the garage on a nice flat concrete floor and it was a pig to use. So what would it be like to use in anger by the side of the road in the pouring rain? I decide that I would carry a good quality modern scissor jack in my car as it is much easier to use. Thus far it has remained hidden behind the seat and has not yet seen the light of day. Tempting fate???
In my garage I use a hydraulic bottle jack and a trolley jack.
My period jack, like my period spanners, period grease guns, period oil cans etc etc adorn my garge to create the right atmosphere whilst I am working in there.
But it's each to his own when it comes to 'originality' in our cars and tools.
A Shelley bantam 7 jack is wrong for a p that's a j jack. A p jack is very similar it's a Shelley jack very similar but has a different code number which I have forgot I used to have one. They are very rare. A for Shelley bantam 7 jacks did you know there are two types. One with a square fitting which is Morris. The correct j one should have a bar in where the handle connects. The handle should have a hook on the end. The Morris hack handle has a square end. J2 jacks aren't that rare but a p type jack is very rare.
Good stuff, Greg. The Shelley A6 for the P type is up there with hens' teeth, but I hadn't seen any specific identification of the correct one for the J. Good to know that it's not just as hard to find. Should it also have a folding handle rather than a two piece one?