Interesting! I've never split my 262's so I didn't notice this difference. In the 1990, 1991 and 1992 IPL's, Husky lists two parts for the oiler tube - the plastic tube (501 83 93-02) and the metal tube (721 42 32-50). In the 262 1994 and later IPLs and all 261 IPL's, only one number is listed (503 66 84-01) for the oiler tube assembly (plastic tube plus insert) so that must be when the change happened.