Thx BAeuro, a useful and concise guide.
I know the 32J/52W variant finds WT+ with a toilet; whereas the 32J/48W variant has no WT+ toilet.
Good to see all WT+ seats are consistent, 2018, across the LGW long-haul fleet.

Would be good, over time, to get seat specific seat widths for these planes; particularly in WT and WT+.

For example, on American's 777-200s (also 10 across in Y, ). Main Cabin extra front row has 17.0 inch seat width, inner of armrest to inner of armrest. Their WT+ seat is 18.5 inch width, inner of armrest to inner of armrest. Also, the AA 777-200 is the only example I have to date of the AA premium economy cabin not having a dedicated toilet.