AFAIK class B is car & E+B is car & trailer. If you have E+ the other classes then you're licensed for a trailer. Mine is a 1979 licence originally & have them all, motorbikes, small trucks etc.
I know that the last time when I renewed my ten year licence I had to have a "medical" for to retain the extra classes... otherwise I would have just been issued with a standard B licence.
I have B, C E+B, E+C1 currently. I did my test at 17 ... just a few years ago
The old licenses were great, my own mother got a free one in the 50's, they just wrote in and got them I understand. Met a guy at the Carrick Hillclimb on Saturday that had one with him actually, he also told me that he heard pics and video of the event would be put up on this new site www.mymarque.com that he's got a profile page on. Looking forward to that, there were some lovely old machines came up the hill, well dome to Carrick on the 50th year too!!