Other ranks type in cast white metal. The star and crescent within a wreath, closed at the top with an Imperial crown. Beneath the wreath three scrolls inscribed ’15 Punjab Regiment’.
Regiment formed 1922. To Pakistan on partition.
15th Punjab Regiment Cap Badge
I see no reason to assume that 1947 was the end of the period of wearing of this badge. The regiment became part of the new Pakistan army in 1947, but Pakistan was still a Dominion with George VI (and later Elisabeth II) as head of state until 1956, when it became a Republic. There was no need to confront the Pakistan head of state by removing his crown from the badge or by switching to another badge (have you ever seen one of the 15th Punjab Regiment post 1947?).
However there was a different badge of the 15th Punjab Regiment with e Sikh Quoit and a Crescent in the center (instead of the Crescent and Star shown here). I assume that was earlier and I assume (but am not sure) that the badge you show came into use after 1947 when the Sikh companies had left. So maybe the start date of this badge as mentioned above should also require a revision.
As said, in 1956 Pakistan became a republic and consequently removed all connections to royalty in badges and regimental titles. For the infantry this was concurrent with a major re-organisation, which made the 15th Punjab Regiment merge into The Punjab Regiment with a complete different badge.
Many thanks Henk van Velden, best thing for me to do is remove the dates entirely and add the formation date to the description. It also seems likely this is a post partition design change version? Gaylor states that the Jats, Sikhs and Dogras were posted to India, the regiment becoming 50% Mussalmann and 50% Panthan which might suggest replacement of the Sikh design. So this is probably a post partition 1947-56 badge?
It is certainly until 1956, and my personal idea (which I developed together with another member of the forum) is that it is post 1947 independence.