I have a small collection of BR▸ (WR) timetables from the 1950s to mid 1970s, and they can be quite instructive. They're all packed away at the moment. One thing that I feel is striking, is that you could travel from Evesham to Paddington in less than two hours back in the early 1970s, in a comfortable seat on a train with a restaurant, or at least a buffet, car. Can't do that now.
Perhaps time to unpack them? My 1974/5 timetable lists one through train taking exactly two hours per day, with 6 through trains per day in total. From December 16th you'll be able to do it in less than two hours on 17 trains each day, quickest at 1h 39m, with 21 through trains per day. The difference on a Sunday is even more stark with just three trains a day then, and a huge gap between 10:33 and 16:58, whereas from December it's 14 trains per day with six train alone plugging that gap.
Take your point regarding restaurants and buffets. Times have changed...