Dunlop and sanket 1950s wheels

can anyone enlighten me with the difference between Dunlop and Sankey 8 stud 1950s wheels and in particular the split rim, I have various Bedford wheel of both makes and was told too many years ago to make sure the rims did not get mixed up, but I cannot remember which rim fitted which wheel, some rims have an s shape at the end for the tyre lever to slot into and some have a straight cut end and the tyre lever hole further along the rim, any ideas please