From what I can tell these appear to be in decent shape and probably just need a good clean. The WoodAndShop site has an article on restoration of these
here. There are three main parts to these planes: the body, iron and wedge. You can replace the wedge and even the iron can be replaced or reshaped. However, if the body is warped, twisted, has worm holes or rot, etc., then it isn't worth the effort. At that point they become keepsakes you hang on the wall.
This is the process I follow when restoring one of these back to use:
- Clean the body and wedge with Murphy's Oil soap. Don't dilute, just dampen a rag and apply the soap. Rub away the dirt and grime. What you often find is these planes were rubbed with tallow to keep them sliding freely across the wood. This tends to leave a black color on the plane over time. You can see lighter spots where the users thumb and fingers gripped the plane. I say this because if your goal is to conserve as well as restore you will want to stop cleaning after the dust is gone to leave this well-earned patina.
- Depending on the type of plane it may have boxing applied in the sole where the wear is greatest. It's called boxing because it was traditionally made from boxwood. Likely problems here is that it's loose or missing. Loose is easy to fix. Just re-glue it with hide glue. Missing boxing can be replaced from another plane or using another suitable wood (e.g., persimmon). True boxwood won't be easy to find.
- If the wedge is cracked or the end is beaten down you may want to make a new one. Functionally, most any hardwood will work. The original is almost certainly beech, but I've made these from maple and oak.
- Restoring the iron requires that you first remove the rust. After that you need to straighten it, flatten it and remove any twist. I suggest reading a couple of articles to understand the geometry and what's needed to make it contact the body and wedge correctly. There is also the question of whether or not you'll need to remake the profile. Again, read up on this. When you get to the sharpening stage first flatten the back and polish this smooth. Only when you're satisfied with the back do you begin working on the bevel. The cutting edge is where the bevel meets the back. Make any fixes/changes to the profile before you start working on the bevel. I have a variety of water stones I use to sharpen these irons. Each one is different based on the profile it makes.
If you do want to sell them I suggest that you just give them a light cleaning and stop there. Most woodworkers who buy these expect to put in a bit of work to get them back in shape. Do some research on the maker's mark stamped into each. You might have a collectible one in the bunch that's worth more than face value.
