We changed from the OEM (winch handle removal style cap) to an SS version with a keyless cap many years ago.
All of them: diesel and waster. (our water fill for each tank is via a fill port on the tank top, inside. Praise Be.)
Unfortunately our type of deck fill with an ss rotating-up lever) does not appear in a search now. That said, there are oodles of SS versions that use a standard two prong opener.
What with replacing the old (and probably overdue) hoses, the deck fill replacement may be the easier part of the job.
Not very "technical" work, just tedious. If I can do this, pretty much any patient simian can do it... !
Good luck!
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)