Here's what we know for sure about Bargman locks: every model has been discontinued and dropped from the Bargman line. Here's the complete list of dead Bargman models (in the order they have been dropped through the decades): H20-2, L-77, L-400, L-66, L-100, L-200, L-300.
At this time there are no after market replacements being manufactured and no OEM parts available. Best bet is watching for them on Ebay, where prices are sky high (supply and demand). Vintage Trailer Supply in Vermont may have used versions from time to time, as may Vintage Campers in Peru, Indiana.
Vintage Campers also sells retrofit lock kits that will fit the openings.