OK, I did a google search, and these were the most direst responses about your weapon and parts search.

The U9 "bolt actions are made in England by her finest old double rifle gunsmiths." Offered in several grades: Hunters grade in 222 & 222 mag., 223, 22-250, 25-06, 243, 6mm, 284, 308, 270, 30-06, 264, 7mm mag, & 300 Win Mag. A Custom supreme grade was offered in above calibers + 338 & 458 mag.


Cabellas currently seems to 'own' the brand name and has some goods that carry the Herters brand.

Bolt Action Rifles - Frank De Haas, Wayne Zwoll - Google Books
Complete information on Herters U9's with pic's

http://www.gunvaluesboard.com/i-have.....-372174.html
Forum about hard to find parts for Herters U9's

Forums.NitroExpress.com
Another forum site for Herter's U9's, but better british info for hard to find parts.