Thanks to one and all! I used almost all of the suggestions made and the end result is much better because of all the great input. Here are the finished gauge wheels.
Hard to see in the photo, but the wheels are adjustable for height on their spindles as well as via the new "top link". The blade can swing freely under the main beam and it misses the wheels as well. There are grease nipples on all three spindle sockets as well as both cast iron wheels. I'm using a chain for a top link to the 3PH.
Here a shot with the "landing gear" up:
It's my first welding project other than some repairs and a few practice welds. I hope it hangs together: it should, the welds are not the prettiest, but I ground bevels on everything and it seems like I got good penetration.
It cost about $150 in materials, plus welding consumables and took about 5 hours to build. I could do another one much faster, I think, but don't plan on ever finding out.
Now I'm going to build mounts for the BB and the rake so I can use the wheels on all three implements.