Just bought this old 1902? Ser. No. 2387019 Omega Valdez 7J 18s Model A?
Can you all confirm that's what I have?
And most importantly at the moment, it looks like I'm going to need a mainspring. There is no resistance when winding.
I haven't done anything yet to clean it up, but I think it will.

Mainspring identification and/or source would be very helpful.
Thanks,

Thanks to Bila for the new mainspring I finally got the old Omega Valdez up and running. Nice old 7J - runs good and keeping good time so far.
This is one of the toughest yet to get the top plate back on. I finally removed the pallet fork and installed it after assembling the top plate.
Not sure that is the correct procedure but it worked.

movement 18s? maybe 16? I dont see many Omegas bigger than 16. It looks nice, and yes, you can usually tell Omega by the serial number style and number and movement designs. Looks like an Omega to me. I recommend you clean it by sending it to my house where I will air dry it and keep it company for 10 years or so. It is nice.

Thanks Andy,
You've got me reconsidering the size. I think you're right, it probably is a 16s. I'm measuring about 43 mm. But it sure seems a lot larger than Elgin, Illinois or Hamilton 16's. Maybe it's the jumbo case it's in. The case measures 58 mm not including the stem.
I can't find much data on these.
Let me give it a test run for a while? and then Ill send it on to you.

Lol, no worries. Look at the size of the case edges next to the movement. They are massive, I just sold a case like this, huge but for a 16s movement. Enjoy your watch, it is a nice one!