Hey Jerod,
You have a couple of options here -
1. Head-space the with the internals out of the receiver.
No need for tools and the spring is easily manageable.
2. With the rifle assembled, You don't really need the head-space wrench. You can use 2 screwdrivers.
One coming from under the receiver through to hold the head-space spring to the side,
and then use the other one from the top in the notches to turn the barrel.
3. You already know about the the wrenches.
James at
http://jjcustom.net/ makes (the only one, i believe) the best wrenches for the 1919.
It's a great tool! Try to pick one up regardless of the type of spring you have or get, you'll be happy you did.
4. You can always modify that pain in the a$$ Izzy "L" spring to work like the USGI.
I've done a few and they work great.
This image was made by one of the guys here on the board on how to grind the spring.
I forget who..

so forgive me whoever I can't to give credit to!