49 State Breather ***'y

"EEC" = Ford's Electronic Engine Control system.
"ECS" = Chrysler's Evaporative (emission) Control System.

The breather cap you're after was used on V8s in '70 in California, in '71 in all 50 states and Canada, and…that's it. It is very difficult and costly to find. If this is just a quicky get-by deal until you replace the canister, you'd do better to simply drill holes in a regular breather and install threaded fittings for the two vapor hoses you want to route there.

And you probably should replace, not repair the canister. See last paragraph here for availability info on new canister. If you do decide to try to rebuild yours, the carbon is just activated charcoal granules you can probably get through an aquarium supply house, and the round filter pad is a commodity item from any parts store, Wix 42998 or NAPA 2998 amongst many other numbers. But you'll probably wind up cursing and swearing and buying the new canister anyhow.