Aftermarket for Model A. Unknown who the manufacturer is/was. I have two and each is a little different. Almost any examination of "Model A Water Pump" on ebay will reveal at least one of these for sale at prices varying from $20 to $100.
If you pull the cover off with the four slotted screws, you'll find the shaft passing through a gob of grease - which is apparently the majority device designed to keep water where water goes and air where air goes. The zerk connects to this inner chamber and if you add grease theoretically in time it will ooze out from under the cover.
Nice in that they don't spray water drops on your windshield like the leather covers prevent. Bad in that there is no stream of replacement parts to draw upon if there are issues. Rebuilding will likely involve tapping into the current line of Ford related parts and "adapting" to make it work.
Joe K