Your Call. Even before all the swing arm near-failures posted here, yours truly SAW [during major Wing maint. in '05] how all un-welded spaces on mine, were shedding water, dirt. I sprayed full can of brake cleaner into all spaces, followed by compressed air dry & several hours hung in direct sunlight.
EVERY space was then sealed with black silicone gasket sealer TWICE. No problems since. DO THIS to your next swingarm and it should outlast you, LOL.
I don't know if trikes are big in the old Country like they are here but I picked up an entire swing-arm assembly with driveshaft and rear-end goodies for (as I recall) 50 bucks or so. It was a takeoff from a trike conversion and was barely used. You might check a shop that does conversions. Also, I see them listed in the Wing-World magazine occasionally.