Mystery British Leather Equipment Strap (Identification Required)

If anyone can identify this WW2 British-made strap please let me know, it was recently discovered amongst some Home Guard items at an old Georgian farmhouse where a former HG member used to live.
The 36 inch long leather strap appears to be devoid of any makers mark but there may have been one present on the small quick release strap but now worn away, due to having a quick release buckle we tend to think it's horse tack related but could be totally wrong,,, any help much appreciated.

Code: 51183