The subject rims are Araya 5H. The 'w/o HP' stands for 'wired-on, High Pressure'. Araya (and other Japanese rim companies, including Kaga and Ukai) called the sidewall impressions a roulette pattern, as they resembled the ball pockets of the wheel used in the gambling game called roulette. Roulette translates to 'little wheel', so the Japanese terminology is, in some ways, more appropriate than the more common 'serrations". The impressions are in the shape of triangles to resemble the stylized 'A' used in the Araya logo. The pattern also looks like an interlocked series of six spoked, though hexagonal, wheels.
Araya's roulette pattern was originally introduced on the wider (1-1/2") 5R rims, with the R designating roulette style sidewalls. They date back to at least 1960. The 5H was a narrower (1-1/4") version, originally offered with smooth sidewalls, with the roulette option being introduced during the 1970s bicycle boom, though the subject samples appear to be early 1980s based on the bicycle's crankset. They are fairly rare but, as noted, not valuable.