I have a 200mm saw blade (41197134200 ) and a 225mm scratcher tooth blade (40007134205) which I intend to use on an FS410c. Could you recommend the correct deflector(s)?

I have had a look on the attachments guide for your machine and this should be the one you need for both blades: https://www.lsengineers.co.uk/limit-stop-225-for-stihl-fs460c-fs460rc-part-no-4147-710-8211.html