Holy chmokes! I can see keepin the miles off a vehicle, but letting it sit totally for over a year, that's not good. And only 26K miles, that thing has sat for more than 98 percent of it's life up to this point.
That's actually sad for the previous owner to allow it to sit for that much of the time, it's not good to that extent. Which I'm sure you already know - I just couldn't fathom letting a perfectly good vehicle go to waste in that manner.
It sounds like you are very mechanically inclined, I'm sure that beauty now has a good home and will be driven at least 2-3 times a week - Isuzu's love to be driven and act up when they've sat too long, i.e. harsh tranny shifting.
Keep a good eye on all of your seals, i.e. rear main seal, valve cover gaskets, etc. It's very well possible they could've gotten dried out enough to maybe cause problems once you really start driving it.
Keep us posted on the progress. Oh, and get those tires off - if they're the same ones that it sat on, you could very well have balancing issues, as well as dry-rot and blow-out's!
Tires, too, like the engine, need to spin to keep themselves lubricated.