This was once a thriving AG region where I live. Now it's becoming one great big housing development. 35(+) years ago, there was 3 Massey Ferguson dealer, 2 Ford, 1 Allis Chalmers, 4 John Deere, and several "short line" dealers with-in a 1/2 hour drive. Now we're down to a John Deere "Lawn & Garden dealer, a Massey dealer that's biding his time until retirement, and a New Holland dealership, a Kubota dealer, and a couple used junk dealers with-in an HOURS drive.(each way) Parts used to be on the shelf. Nowdays they stock filters and hats. Anything major comes from a central parts depot.
Enter Al Gores internet! I can email any number of dealers and a few discount parts houses with part #'s and/or descriptions of what I need and UPS/FED EX/USPS shows up at the door with my parts in as little as 1 day in some cases with parts in hand. Go after them myself and I need to go order, come home, drive back AGAIN to pick up, then drive home AGAIN, burning that ever increasingly expensive fossil fuel.
For "dealer only" hard parts, I'd highly recommend having a parts manual for whatever it is you'll be needing to order parts for. Give them the # and that way you don't have to trust to luck that they looked up the right #.
Long story short, it's QUICKER, CHEAPER, EASIER, and just all 'round BETTER than doing things the old fashioned way.