Whoa! I just posted and saw Spirals post.....ridin' in like the cavalry w/pennons flappin'!!
Thanks Spiral ! Again, you really pack the heat with British military material!
As you mention the 'P' might indeed represent police, and India did maintain mounted police well into the 20th century in various regions. Do you have a reference resource that offers data on these markings? I wish I could think of the title of the handy little booklet I have somewhere!
All the best,
Jim