Vintage circa 1920s -30s white cotton British naval/ services chore pants.
 
No issue or size label. 
 
White cotton with v back and buckled cinch belt. Cream buttons around the waistband for braces/ suspenders and buttoned fly. Side pockets and small ticket/ change type pocket.  
 
Some rust type marks at the seat, a few spots on the legs. One of the waistband buttons is chipped- see photo.  There are some small fray holes at the upper back, on the legs.  Small rust type mark inside the hem. General minor wear. 
 
Laundered.
 
Measured at 37" at the waist in total uncinched- can be cinched in a couple of inches using the back belt and buckle 
31" inseam/ inside leg 
44 1/2" outside leg length
9 1/2" across the hems
rise is 16 1/4"
21 1/2" across at approx hip level (these are men's pants however and will fit women differently)
14 1/4" across the top of the leg at the thigh, side to side
24 1/2" across the front, side to side at the base of the fly