All self propelled cranes are considered "special mobile equipment" in missouri. No titles, no plates. Buy a one way oversize/overweight permit to drive it. You will have to have insurance to drive it. (sorry, I just read your last post and you already covered your knowledge of that, I type too slow I guess)
My permits will simply list the make model and year of crane, and it will be listed as self propelled.
I have flat towed a crane, both my 70 ton(93,000lbs) and a smaller crane, behind a wrecker, you would want to have the crane running for air for the brakes, or have a air line from tow truck to "trailered" crane. A towing company would be able to tow it, because then it would fall under their insurance. We only flat towed both a few miles when needing repair. I only flat towed because I couldn't get the front picked up because of weight and the hydraulic boom in the way. Its not fun, but I never built a tow bar either.
Looks like military 20" rubber , on budd's(?) if they aren't 1400r20's (its hard to tell the tire size from the picture), you should be able to slap a set of 22 or 24.5 rims and rubber on there, if you aren't worried about the tires, run em.
If you knew someone with one of those 5th wheel hydraulic tow bars (I think the commercial name for one brand is "pro tote"), you might be able to get the front end off the ground with one of those, and then pull the axles and driveline.
Send the counterweight and boom and clam with the second load, and with the house swung to the front, it probably isn't that heavy on the steer. To keep it real low, you could pull the steer tires. With it swung to the front, the house counterweight would all be on the rears. I have never pulled anything with one of those 5th wheel tow bars, but I see salvage guys with garbage trucks on them. I do see the 5th wheel totes for sale quite often used for around 3k or so.
If I was trying to get it home on the cheap, I would lean towards a 5th wheel tow bar, eliminate the second driver, and check/ grease the wheel bearings before I left. With the weight off, you say you're under 54, so plus a 20,000lb truck and a 2k tow bar, I think you are legal.
I'm wondering if a "temporary" "intransit" tag would be the way to go, pulled by a truck. You know the salvage and towing outfits don't mess with titles on everything they haul all over. Just like when they piggy back trucks from place to place.
I don't know if you have the 5th wheel truck? Its hard to list the possible ways that you could get it home, I don't know what you have available for equipment, sorry.