Post a "Want-To-Buy" ad for 4x5 film holders here on APUG - I bet you will get some offers.
“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”
Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2
I have three Lisco Regal II 4x5 film holders which I posted for sale several months back for $15/each. No takers at the time so they are still available. I bought them new about 20 years ago, used them only a couple of times.
Not sure if they fit graflex though. I don't know much about graflex.