If you can be doing with undoing the carrier nut again and removing the carrier youll see what ive been saying about 5p 10p etc, If you can then get it in the right position you may not need to buy anything else! And youll be able to mark the sweet spot!
Paul what make rear sprocket carrier have you got, I have a few sprockets around that I use for changing the gearing when racing, I could see what I have got, most are a 520 pitch but some are 525. I will look in the moring and if I have a 36 or 37 you could borrow it while you see about sorting the chain. I have chain splitters and riviters as well and I usually get my soft links from what was M&Ps next door to Fox's diner. If I have a sprocket it may be worth you coming up on the monster or in the car tomorrow.
Mine are all different to that one Paul, I have Renthal and AFAM sprockets to fit my Renthal carrier and the other one is Valtermoto and they all have a diffent pattern to that one on Ebay, all mine are less square shaped around the cush drive area.