One day while out on your Ariel a guy will step up to you offering a pukka '28 Ariel fork as a swop for your BSA one.
So no worries there, just wait for that day!
In the meantime; enjoy the ride.
Cilinder head looks good, no broken out holes which is often the case after a previous ham-fisted owner forced the rockerbox bolts down a clogged up hole. Although those breakages can be repaired it is a job you can do without.
keep up the good work !