Raleigh USA did not introduce the Technium series until the 1986 model year. Your frame was built on the 64th day of 1986 in the Kent, Washington factory, so it's definitely a 1986 model. The 460 was the middle of the three Technium models offered that year and the MSRP was $290 US. The subject bicycle does appear to be the 21" version.
Link to OP's photo album:
https://www.bikeforums.net/g/picture/15190840