Who wouldn't?  A box blade, for example, is a box blade.  Slap a PDF parts manual up on your website and fire away.  Or, as you have suggested, send an extra cutting edge.

Seems to me that the general dealership model is predicated on (1) see it on the lot, kick the tires, get some advertising that way, and (2) specialized knowledge from training, setup, and experience, and (3) hidden knowledge, as in the parts and service manual not public, or extremely pricey (like CAT service manuals),  (4) time-and-place utility, as in it is there 10 miles away, and parts are there 10 miles away, and (5) subcontract out repair labor, instead of keeping someone on staff, training, etc.

YouTube and easy-to-read CAD drawings make it pretty easy to test-drive a product virtually.

The web generation and smartphones have made it pretty easy to disseminate information and support a product remotely.

If it's not something that would require emergency parts, or you are moving products to a producer who understands the value of up-time and keeps a set of spares in his shop, the time-and-place utility for a dealer in this situation is less, and if it's simple to repair and not prone to breaking, the service value is less.

The dealership model seems to be centralizing as they are facing this same reality.  If the local parts market doesn't support a nearby dealership, the service side drives to larger, more concentrated facilities.  See: Bron tile plows, CAT dealerships.  What is more centralized than factory-direct?