Ok, I have part number updates for anyone that may need this for a future project. Couldn’t find a Smart part number for #1 but an O-ring with dimensions 1 1/2” ID x 1 11/16” OD x 3/32” wall is about as close as you can get, BrassCraft #SC0606. #’s 2 & 3 are the same, Smart # A0219970645. The coolant hose connection, #4 is Smart #A0199972945. Not marked on the photo but may be helpful is the cranks shaft seal, Smart #A1320320080.
In addition, if you’re OC like me and want to replace now while you’re in deep, here are a couple other part numbers for the project, sorry if this is a duplicate from the part number sticky. The seals between the spark plug cylinders to the valve cover are Smart #A1320150080, you’ll need three of course. The alternator/water pump belt is Gates #K040315 and the A/C belt is K040289SF. Most of the other parts were fairly easy to identify. Good luck to everyone that’s diving into this work!