RAFT is an organization that might have some ideas for you:
RAFT - Renewing America's Food Traditions
You've probably read it, but they published this booklet with Gary Nabhan about heritage apples:
Forgotten Fruits Manual & Manifesto - Apples
This is a whole page of other documents on Place-Based Foods, some compiled by Gary Nabhan:
Gary Nabhan Place Based Foods - At-risk heritage foods from around North America
You don't say your location, but State-based programs are often the best bet for small, local, heritage type programs. Some states have historic preservation grants, for example. I'd probably look for that first. That seems like a historic preservation type project to me, unless you are going to end up marketing them to sell.
ATTRA is a good place to look for small farm and organic farm grant opportunities, not sure if any apply:
ATTRA – Sustainable Agriculture Program funding page
Also if you are in an urban location, the USDA has special programs for urban farms:
Urban farm grant opportunities
The Urban Agriculture and Innovative Production (UAIP) Competitive Grants Program supports a wide range of activities through two grant types, which are Planning Projects and Implementation Projects. Activities include operating community gardens and nonprofit farms, increasing food production and access in economically distressed communities, providing job training and education and developing business plans and zoning.
Here is a whole page of types of grants available for marketing farm products - which may not apply, but I'm putting here for posterity's sake:
Agricultural Marketing Service grant opportunities through USDA
If you still can't find anything locally, you might try things like looking at who the grant recipients are of these types grants above. Many times they are non-profit organizations securing funding for local projects. You might find one in your state that just isn't easy to find.
Farmers Market Promotion Program awards 2017-2021
And then last but not least, with a small project it may just be easiest to solicit donations from locals who care.