Which if any of these;
http://www.e-gunparts.com/DisplayAd.asp?chrProductSKU=881550A&chrSuperSKU=881550&MC=

would work best on a 1903 action? Any help appreciated.

I don't think any of these Mausers would work on a springfield. The rear guard screw on the springfield is angled and the bottom metal would not work because of the different hole spacing. You could buy some aftermarket stuff or have your original milled springfield bottom metal modified at no small expense for either.

It can work... will take at least 4 hours work and rebluing
jeffe

Hmm, sounds like its beyond my very limited "tinkerer" skills, thanks anyway guys!

What about this one?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=585&item=2248215998&rd=1

If not that one, there are a bunch of them just search on "springfield trigger"

I agree that putting a Mauser triggerguard on a 1903 Springfield is an excerise in futility. The Springfield triggerguard is better looking and also lends itself to a more pleasing line in the grip of a stock. I would just spend the money and have the springfield floorplate hinged if you need a hinged floorplate on your rifle. I am assuming that you already have a milled triggerguard as you mentioned it is a 1903 and not a 1903A3 which had the stamped metal guard.