After putting this off for ages I am going to do it this evening 😀

Go I just need to flat back (100grit) the current surface first before re-coating?

There are couplf of small places that may need a bit more work but is it straight forward enough?

100 grit sounds a bit rough.
What’s it been oiled with previously? Danish? Tung?
To re-oil I’d have thought you could use something finer just to clean it up really, perhaps even a kitchen scourer (Green washing up thing)

Oil is mega easy to apply really. Follow the instructions on the tin but when I finish newly made stuff, I tend to just wang it on, leave a couple of minutes to soak in and then wipe off the excess with a fresh rag.
Build up a few coats like that. Pretty easy.

an old boy i used to work with said you should oil wood once a day for a week, then once a week for a month, then once a month for a year then it never needs treating again.
balls to that though, just give it a scrub with a ‘scotch-brite’ pad and as kayak says “wang it on”