rebuilding gearbox question

So I have a 2a gearbox (inside a 3 cover). I am replacing the thrust washer (as the old one was a few thou thinner than it should be) and also the washer with the blue arrow in the picture, which has a tab.
At the moment, the washer tab stops the washer going past the point marked with the red arrow, and it would certainly not fit into the indent in the bronze bush.

I could apply force to get the washer and its tab further along the shaft.
Or I could file down the tab so it moves more freely along the shaft and also fit into the indent.

But i don't want to do either of these if I am missing something.

I have looked at the videos on youtube and can't see anyone reinstalling this washer, so i feel theirs just slipped on without issue.
I am afraid i can't track down the old tab washer to compare (it is taking so much time to get this gearbox sorted, esp given my inexperience).

Also taking ages to sort my box. [ not inexperience in my case just lack of memory as 40 years since I last did one! [ see missing reverse thread]
Strange thing is I bought some different size thrust washers [ blue one in pic] to set gear end float and none had a tab. Mine is a early series 3 box. I did wonder why the bronze bush had a notch in it when there was nothing for to locate in it.

I have some of these washers left over from my early S3 ‘box rebuild. If anyone needs one, let me know the size and I’ll check what I’ve got… they have the tabs, and they slide straight on with the tab in the spline. They are genuine ones from Blanchard… so might be useful..

I am more confused now.
I realise it is not the tab that is causing the issue, it is the diameter of the shaft versus diameter of the washer.
Above the washer in the picture the shaft is about 1/4 of mm wider than the shaft below the washer: this is
a) from using a callipers to measure it and also
b) when i put the bush on the shaft, it is snug when it gets to the wider part but has a little bit of movement below it (i.e. the slightly narrower bit).
So I am sure about this.
Hence the washer only making it slightly over the place where the circlip goes, and i am sure it needs to go further.

I have no idea if i have a weird variant of a series 2 shaft, or whether this is standard.
And what to do about it.

That is as far as that thrust washer needs to go, just enough to get the snap ring in the groove, Different thickness's as in your pic to set gear end clearance.
Have a look at "steamwally series gearbox" overhaul on the You tube for explanation as how. Much the same for 2a and 3 box'3