Here's the low down on the lo-boy. Basically a mowing machine (as setup). You can add a snow plow easily, and they can typically be found for $400 or less. With the high flotation rear tires, you'll need weight and chains to do any type of pushing snow or gravel. However, the better option would be to grab a set of the narrow, ag-tires like is on a standard Cub. They were also standard equipment on the lo-boy tractors, and those are around and easy to find as well. Also, as setup, this machine will easily pull around your 24' boats and work out very nicely for that. A simple bracket hitch either on the front or back will handle the boats. 1st gear is low enough to do any of the work listed above, with PLENTY of power.
Without the 3-point hitch, you won't be doing any field plowing, disking, cultivating. That's about all you're loosing with the hitch. They made a tiller, but they're hard to find and very $$$. The PTO on a lo-boy turns at engine speed, wrong direction, and the output shaft is smaller than a standard 540-rpm PTO, so there's basically nothing else you can run with it than a mower.
The creeper gear is not really needed unless you have a tiller or snow blower (also near impossible to find) so really, you're not loosing much by not having it.
Rebuilding the PTO is one of the more pricy items to deal with, but once done, it should last MANY years. You're probably talking $300 to rebuild it or buy a rebuilt one.
If you're just planning to get the machine running and operational, you're probably looking at another $500, and that may be on the high side.
Tune-up (fluids, belts, plugs, wires, cap, rotor) probably $100 to $150, but you have to do that on anything you buy, so probably shouldn't count this.
Fixing the electrical problem - rebuilding the starter/generator - $75 to $150. Replacing the voltage regulator $50. Anything else is probably a short or a disconnected wire (I'd start with the one you found off the VR), and is just going to be more annoying to find than costly.
If you want to go all the way, strip her down, install a new grill surround, paint, decals, etc., plan on spending $1000. Paint and the grill surround will be most of the cost. Honestly, that machine does not look bad at all, and I'd get her running good and usable long before I'd even think about taking her the next step. Don't worry about the beat up grill surround, most of the 154's out there are just like this one.
I'm like others, if it were my neighbors and could be had for $400, it would have been in my garage before I ever posted on here. The rear tires cost more than $400 to buy. That's a decent looking machine, and should be able to get running with minimal $$.
Front end loader...... Well, they made one for this machine, and it will handle it quite well. However, there are limitations. The hydraulic pump for the loader will run off the PTO, therefore you cannot run the mower and the loader at the same time. So, you're either looking at another machine for the loader (or mowing), or come to grips with a couple hour time needed to change out implements. I'm not sure I would factor this into the decision on this machine, unless you really need a loader now. Having used LOTS of front loaders on tracors, I can tell you that a loader on a machine that needs to have gears shifted just sucks! I'd be shopping for a more modern machine with foot controlled drive control and hydostatic transmission. Also, if you are planning to have one machine now, that mows and has the front loader, then I'd be looking at newer machines with loaders that walk on/off. I can have the FEL on my new Simplicity Legacy XL in about 3-minutes, regardless if the mower is on or not (it will work with the mower installed). The other day I had a load of mulch delivered, so I went to the barn (mower on the tractor), hooked up the loader (left the mower on the tractor), moved 4 yards of mulch, and went back and unhooked the loader, all in about 1-hour, then mowed the lawn. You'll NEVER do that with a lo-boy.
Cub Cadets 682, 1811, 1864, Simplicity Legacy XL 4x4 Diesel with FEL, 60" mower, 50" Tiller