1931 Small Eight: Plugged Ports

I need to be certain of the identification and purpose of the ports in the photo. All but two have red plastic plugs from the rebuild shop; one has a fitting with blue tape sealing it, just to the rear of the oil fill port (large red plug).
The small plug near the rear and below the block side plate is I believe the port for the coolant drain valve. The small plug just below it will be behind the starter and appears to be in the lube oil pressure gallery: oil pressure to the dash gauge? On the head higher up, the coolant temp sender port in the head is obvious; it does not have a plug.

The large red plug is the lube oil fill port; just aft of it seems to be another port in the lube oil main pressure header; toward the front looks like another port in the oil pressure header: is this the supply to the lube oil bypass filter? Is the small plug lower down the block and just forward of the oil fill port, the bypass filter return to the crankcase?