OK, that manual from New Zealand looks to be nothing more than a fancy republished factory manual. You can find used originals for much less, usually under $20. As mentioned in it's description, it's a 1975 base manual that includes supplements for the '76 and '77 models. Yamaha didn't publish a full manual for every model year. Full manuals only came out every 3 or 4 years. The model years in between got smaller supplements outlining and differences or changes from the previous full manual. Your '77 model is one that got a supplement so you would look for the previous full manual that included it, something like this .....
You can download copies here .....
https://thexscafedotcom.wordpress.com/2011/01/10/xs650-manuals/
They also have parts manuals.