The payscales on PPJN are a little bit off, since they're from a few pay rises ago (2.6% then 0.9% then 4.7%). So compounding that to get the current rates multiply the PPJN ones by something like 1.0839. A Year 1 SFO then becomes £47210, which my favourite tax calculator reckons will give you £2800-odd with let's say £200 quid a month allowances to add on too...