Well, basebase. As the owner and lover of a Kawai RX-5, the younger sister of the RX-3 (remember, the Japanese like to skip the number 4), I'm sorry to say that I think you have cause for pause. Quite a bit of it. It's not really a pleasure to deliver this kind of news, but I hope you'll forgive me if I have a little fun with it. After all, it's better to laugh than to scream... most of the time.
This "tech who inspected it,"
who "didn't seem too alarmed"
by this system of of deep, chevroned cracks--- literally, too many to count--- and says that "They are fairly typical for pianos of this age". (They are not). Who says that "they don't seem to have an effect on the piano's tone".
That might be true, provided he heard the tone before the cracks--- is that the case? Does he have recordings?. "The cracks seem to surround the bridge. Should I be concerned about these cracks?"
Well, this is the kind of spilled milk that it doesn't do any good to cry over. It's not even your milk, yet. But, I'm curious. Tell me, who paid for this consult? If it was not you, and if you're serious about this piano, I would insist on getting a real one from a real tech, one whom you have some reason to believe knows about pianos. If you don't already have one you trust, try http://ptg.org
Piano Tuners' Guild. I read "Grand Obsession"; I know it's Billings, but they should be able to give you contact information of techs who are at least relatively close. My tech in California belongs. I can say, at least, that their RPT members have met tests, which assure the public that they meet, or surpass, at least a minimum standard of proficiency. Lots of candidates have to take these very tough tests more than once. That, and as full members they subscribe to a code of ethics, which is all spelled out. The main thing, boiled down, is that they say, as a body, that they mean to do right by the customer.
I can't help but wonder what the president of PTG would say about the gentleman who has already advised you so poorly. You could ask. I was going to say, and now it doesn't sound quite right, but oh well: And PTG supports a program of continuing education for its members. And, they offer consulting service, for those stumpers. It's significant support for the industry.
As to what might have happened, really. I'm not a fortuneteller (you might need a teller of misfortunes, anyway), But, let's just see. I believe Montana has cold winters, if I'm informed correctly. Pianos were invented in Northern Europe, in a time before HVAC, or any kind of climate control. Pianos are not really bothered by cold. What pianos do not like, is going from very dry winter air (it's dry to begin with, and heating it makes it even more dry), and once Spring comes along, going to very juicy wet air. And no sooner do they get used to that, and here come the holidays again. What they do like is even conditions, the year round. I have heard that some very long-lasting pianos have been seen up in your neck of the woods, because they like the year-round dry air.
The classic awful gigs for pianos are: teaching piano (like in a school or studio), church piano (encountering extremes the year round, and often beaten nearly to death because they tried to make a a too-small piano sound like a big one, able to be heard over all those voices). Then there are bars and clubs...
You know, I'm pressed pretty hard to believe that adverse conditions like that, even continued year after year, could have raked the wood by the bridge so drastically. Kawai's are seasoned for North American conditions, and they are built to take plenty of use and even some abuse. Maybe they rolled it out on the back porch and threw a tarp over it once the kid went away to college. Or who knows. There are floods; there are hurricanes. Maybe someone from Kawai could hazard a better-informed guess. http://www.kawaius.com/
If it will take and hold a tune, you may be able to get an idea for yourself of its voice, and its action. That is how I bought my own piano: with my ears. And, what I now know is that it could be worthwhile to buy a Kawai just for the action. And your own tech can listen with educated ears. He or she can not only assess it for condition, tell you what needs repair, and give you an estimate of what it might cost to put it in good shape, if that is possible. In addition, they can give you an estimate of its value in the local market. Ask for these services when you are booking the inspection; they'll give you a little written report--- it's a check-off list of the various things they see, as they assess. They can include photos as they go. Not the kind of thing that costs a lot more, to have them added to the report.
Best of luck to you! Let us know. Bringing a piano like that back from the edge would qualify as a very good deed