So as noted earlier, I decided to tackle this myself and see how it went. I'm happy to report this has gone from a not too fun job to a not too bad job. As with most things, you learn a few things that make the job a little easier as you go along. That has definitely been the case here.
This is what I started with. That window wasn't dirty, that was all between the panes...
This was working on it - I had to take over our bar for a few days... :B
And the finished product, reinstalled...
That went well enough it was time to do the others. These (2) are both done, the back one has been reinstalled, the front one I'm waiting for a little help getting back in, that one is heavy. The one remaining still needs to be done. That's the emergency escape window so the framework is a little different. Same deal, with a little help removing it I think I can leave the original outer frame in the MH saving a little time overall...
If anyone decides to take this job on and would like some moral support please feel free to ask - it's not really that bad of a job.