I would bet you have an Arrowhead Sillcock. http://www.arrowheadbrass.com/
I've been to Lowe's and to a local wholesaler of plumbing parts and both have sold me a replacement kit for a vacuum breaker (anti-siphon) valve on my outdoor faucet. Neither of them will work because they have coarse threads and the original one has fine threads. Any vendor on the web that might have a replacement? There doesn't seem to be any brand on the item so I have no idea the manufacturer.
I believe you might be right after visiting their website. It didn't look like they had a full kit to replace the valve and the cap. Do you happen to know of the part number(s) offhand?
I can't really see any identification on the faucets. I know they were installed when the house was built around 1994.