The 69 Camaro Hurst shifter OEM or aftermarlet shifter should both work on a 1972 Saginaw trans if it has the threaded bosses like the 69 Saginaw.
The same OEM 4sp Hurst was used on the Saginaw and the Muncie and the OEM Sag mount plate is the same as the SB Muncie mount plate. The rods and trans levers are different
For some reason, Hurst did not list an install kit for the 69 Camaro with Saginaw, they told you to use the original factory rods, levers, and mount plate with the new aftermarket Hurst shifter.