MWS5101EL3 was a 350nS part. Not the speediest in the world but works in most locations.
HKUTSource is a known counterfeiter.
Those appear to be legit by looking at tooling holes but difficult to tell.
When Harris was making components, we always used 4-digit date codes and did not use 3 digit date codes. Not sure what GE or RCA used before being acquired by Harris but the three digit date codes on the Harris parts look suspicious.