It appears to be an early track bike (track rear fork ends and fork crown not drilled) that's been modified with a second rear bridge (both drilled for brakes), probably to take wheels with 27" road rims as well as 622 tubular rims. The fork dropouts look original. P138 would be ~1947.
That's one very rough Paramount atmo.
__________________
- Stan
my bikes
Science doesn't care what you believe.