Eddystone mfgr 1917 US Enfields are considered the least desireable of the 3 mfg'rs of that rifle.
Before all the feedback on how well your particular Eddystone has served you and the Doughboys of WW1,,that is just a fact of comparing the 3.
Remington rates 1, Winchester 2 and Eddystone 3.
The Eddystone Arsenal was the old Eddystone Locomotive Mfr'g Works in Eddystone Pa.
Yes Remington provided machinery and mangment.
The rifles made at Remington Ilion are considered the best overall quality. It's just that way.
Many custom builders will not use an Eddystone action to make a rifle up. They will not 'waste their time' on one. High brow?, maybe. But it's their time and your money that's being spent and when you get deeply into these, you get to know the differences in them.
All that said,,
Are the 'Actions' being offered actually 'Actions',or are they just 'Receivers'
The former are complete with bolts and all the parts including bottom metal, trigger assemblys, etc.
The latter are just a frame, stripped of all small parts, no bolt assembly, trigger guard, magazine box, follower, bolt stop, etc.
Big difference.
Eddystone mfg actions are well noted for developing a crack in the front receiver ring when the orig bbl is dismounted.
This comes from the way the orig bbl was torqued into place.
Not every one devolpes the crack, not every one is a bear to dismount the orig bbl.
The safe way to remove them is to relieve the torque at the bbl/frame joint with either a hacksaw slot all the way around on the bbl. Or use a lathe to do the same. Not much is needed. Then the bbl unscrews rather easily.
When they do crack, the crack is generally on the underside of the front recv'r ring where it is thinest. Usually easy to see.
The Eddystone recv'rs can be brittle sometimes too. Not unlike the Low# '03's and break off a rather sizeable chuck from the ring if already cracked.
These big actions have been used to make up some great big bore custom rifles. All the way up to 505Gibbs.
But the choice is usually a Remington, Illion made action for their better quality.
Bbl's for the action are hard to find if looking for a exc condition replacement Milsurp or a pre threaded & chambered sporter.
Most any of the Bbl makers with make, thread and chamber & fit a bbl to the action for you. But that'll run you into the $500/600 range by the time you are through with shipping.
Building a sporter from parts is not cheap any more, especially on actions like the '14/17 Enfield and even the '03 Springfield.
The 98Mauser isn't too bad as there are still quite a few sporter bbls around both secondary market and new prehtreaded/chambered at decent prices.
Lots to choose from in pre-turned stocks as well.
Doing much of the work yourself helps to keep the price down and makes a nice hobby of it.
Searching the shops and shows for other peoples started but didn't finish projects can also be a good source of something to straighten out and finish up at little cost other than labor sometimes.
I've found a lot of gems that way!
Good luck in your project(s).