Weights? Glyphs coverage?

The following Google Fonts (www.google.com/fonts) are similar to Norpeth, to greater and lesser degrees, and are available free for print and web. Perhaps one of them could work for you:

Play, by Jonas Hecksher
Cuprum, by Jovanny Lemonad
Maven Pro, by Joe Prince
Exo and Exo 2, by Natanael Gama
Armata, by Viktoriya Graboska
Ropa Sans, by Botio Nikoltchev
Doppio One, by Szymon Celej
Ruda, multiple designers
Lekton, multiple designers

Some commercial fonts that are also very close, and which come in a full family of weights:

Klavika:
http://www.myfonts.com/fonts/processtype/klavika/ [single-story |g| available as stylistic alternate]

Sentico Sans:
http://www.myfonts.com/fonts/dtptypes/sentico-sans-dt/

Coupe:
http://www.myfonts.com/fonts/t26/coupe/ [double story |g| only]

Soleto:
http://www.myfonts.com/fonts/daltonmaag/soleto/

Klint:
http://www.myfonts.com/search/Klint%20Rounded/fonts/ [double story |g| only]

Gustan:
http://vllg.com/luxtypo/gustan

Great Escape:
http://www.myfonts.com/fonts/typodermic/great-escape-rg/