Although very similar to the one made for the Australian market, your Hercus 260 does indeed look like a USA spec model.
The rear pulley shaft has a feature that supposedly makes it easier to change the belt, although it is still a bit of a pain. There is a bolt that can be undone on the right hand side, which allows the shaft to split and provide a small gap for the belt to go through. It's explained in the Hercus 260 manual, which can still be bought. See ebay item 201708758076
You still need to dismantle the main spindle though. The puller is described in this other maintenance booklet attached here, along with a 260 brochure.
I like your lathe so much, I'll request that if/when you are inclined to sell it at any time, please let me know!
jprincic<AT>gmail<DOT>com
Jordan