OK so then I had to do the corresponding hockey cuts and dog bone cuts in the end of the smaller piece.
Did the hockey cut - no problem
Did the dog bone - again no problem. As the wood is hard you had to do the cut in about 5 or 6 smaller passes so it's not a speedy job.
It was just as I finished the last of these 3 dog bones I realised I'd f*cked up.
I'd forgotten to turn the board over first so I'd put the dog bone holes in the top side of the worktop.

So I cut off about 8 inches and did it again - properly this time
F*ckup number 2
I went to bed that night quite pleased with myself. I'd cut the end piece properly this time and all perfectly square.
Then as I'm lying in bed I started to think that the walls of the barn aren't perfectly square.
The next morning I went back and checked

Oh Bugger.
I scribed a new line that would work with the walls, cut off another 8 inches and did all the cuts again.
Luckily the end piece was a bit on the long side so I'd got plenty of room to spare.
This is what it should have looked like (and now does)
And this is the finished article (prior to oiling it). You can also see the car lift control panel which now features slots for the rubber blocks
I did actually do one final f*ckup while rounding the corner and the router moved in a bit. I've filled the resulting indentation
And a view from the bottom end
It feels great to have all this worktop space