Yea you can get dutch oil , anywhere.
If the wood looks fine though , why mess with it , unless you want to for fun.
Ok say the finish (whatever it might be) is uneven or wearing off in spots , I would grab some de-natured alcohol and clean off the rest of the finish (pour a little onto a rag and just rub the wood till its clear of finish) , let that dry.
I dont know how dense spalted sycamore is but I'm assuming it's fairly hard.
Also I'm going to assume dutch oil is about the same as tung oil here.
I use tung oil , i put a dab on my finger and work on the wood so theres a little layer of it , let that soak in if it will , if the wood is thirsty , apply more oil until it wont soak up anymore then wipe off with lint free cloth , make sure to rub off any you get on the bolsters/etc.
Let this dry , some woods take a few days for it to stop feeling sticky or tacky , depending on how hard/dense they are.
When it is good and dry , apply a dab more and rub this in with your finger , polish off with a lint free rag , I find this method to leave a nice shine without looking too glossy and fake , make sure though you dont leave prints , it takes a little practice but it's really not hard to do.
If you can take off the scales (like if they used torx screws) , all the better.
After you use your dutch/tung oil , there's no need for wax.
