Rex, Just nipped into the Engine Shed. My Early Plunger case has a hole of 46mm. The scroll sleeve is a Gnats's Knacker under this and is a tightish minimum clearance fit. A smooth edged sleeve the same, but the smooth edge is wider than the scroll. Both sleeves are 56mm long.
Also in the assortment is a later swinging arm sleeve, 51mm long. This is used with a spacer that runs on the later oilseal. However, this is just a shade under 43mm. diameter. So it looks as if the problem is down to an incorrect size of sleeve. Track down the correct part as I have detailed earlier, and you have sorted it. No need to rip it apart again!
The early cush drive on the early S/A had a single piece drive sleeve, so I would guess this is also 43mm, and this incorrect part could be what you have and the reason for your leak.
Swarfy.