I found the best place for buying parts is from a 'small' RV dealership in your neighborhood.
They get shipments everyday. No hassle of trying to chase down your delivery when it doesn't arrive when you order on line. AND more importantly you have a human being to talk to face to face.
they have often prevented me from buying the wrong part and/or often have given me suggestions of how to fix rather than replace. Because you are dealing with an experienced RV person rather than some clerk in a warehouse just punching in numbers for an order placed on line.
I no longer buy anything on-line that pertains to my MH. It's either the local RV dealership or my Mobile RV Repair Guy.
We must be willing to get rid of the life we've planned,
so as to have the life that is waiting for us.