Sorting Office 1946 Hebrew-date postmark error on 1948 Jerusalem mail

Sorting Office 1946 Hebrew-date postmark error on 1948 Jerusalem mail
1948/"1946" Hebrew date cancel error: 3-9-1948 local JERUSALEM stampless official mail from Health Ministry on requisitioned OHMS stationary to local Moshav Zekenim (geriatric facility) tied by JERUSALEM 2 Sorting Office cancel whose well-struck Hebrew date of 29 Av is correct except for the year, which is here "1946". An error in the assembly of the metal datestamp. Undocumented - discovery piece. Opened gently at back, small tear/piece missing at right-base.