4X5 Tri-X film pack questions

I have no idea how long I have had this film pack. It was in a film pack adapter that must have come with a 4X5 camera I had purchased years ago. It has 3 of the images already exposed. I don't know if the exposed sheets have been robbed from the pack or if they are still in the pack. I'll find out when I open it up to process a test sheet.

Anyway, I recently acquired an empty 4X5 film pack adapter for my Graflex Series D and intend on finishing the unexposed film. Since I have no idea how far expired this film is, can anyone advise on what ISO would be a good place to start, and perhaps a good Rodinal dilution to use for processing (Rodinal is what I have...but may have some D-76 powder as well). I'll probably shoot a test sheet or two and process before going thru the remaining 10 or so sheets.

I remember back in the 80's shooting 4X5 film packs when they weren't expired :(

LOL I will jump in. But many here use old film.

I have heard and tried losing one stop a decade.

I really believe in Rodinol especially at 1-100 distilled and 20 minutes at 68F and agitated.

I'd personally start digging for the D76 powder and expose a sheet at 200 or even 100 to see what comes out. Rodinal doesn't sound like the ideal candidate given this situation - but then again, the situation isn't exactly ideal to begin with, so what gives huh ;)

HC-110 is the choice of people who develop old 'found film', apparently for its low-fog qualities. Somewhere on www.westfordcomp.com. I don't think it matters much here. Film pack has been gone since 1992, and who knows how old yours is... so you're some ways off the map. Kodak products pre-1972 or so used the serif typeface on the logo, which may help place your pack to within a decade or so.

This is what got having just acquired two packs expired 1981. I developed in HC110 dil:B for 8m according the enclosed data sheet.
Shot with flowers rated at 160 and used flash.