Maybe the starter solenoid is getting stuck? How do you know it is not the starter that is going on you? I seem to recall starters on their way out have a tendancy to fail when it gets colder out. So give it a love tap with your wrench and see if she fires right up.
There's only one facility here that sells biodiesel so it's a rare commodity at the moment. The few people that have run it say that they have not noticed any differences in performance. But I would imagine that the fuel filter will get pretty gunked up.
A better alternative to a dash mounted fan is a 12 volt portable hair dryer/defroster. Just search on google for "12 volt portable hair dryer". You will see pages and pages of results. They work great.
Just like with sticky brakes on cars, if the brakes are released, start moving the equipment a bit and it should break free. Hope that helps. I know others have already mentioned this.
I agree with what one of the posters said by keeping the loader uphill. Also avoid driving parallel to the slant as I find that makes it the most unstable.
That's a really nice snag. If it starts and runs good, doesn't matter if it was abandoned in the past. What matters is how it operates today. Sounds like you got a nice clean running machine there.