I'd start looking for tires and inner tubes. Decades ago I read somewhere there wasn't anybody producing them domestically. I honestly don't know if that's still true or not.
Frankly, however, I think it's a moot point. The last time that I bought inner tubes for my recumbents, I had trouble finding ANYBODY who had the exact size and valve stem length that I wanted in stock.
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My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.