Eric Hendrickson (http://pentaxs.com/index.html) is considered the "go to" pentax repair person. He would be your best source for an estimate. However, if you shutter doesn't fire, hard to know what is actually wrong.

But, IIRC, the 67 won't fire without film in the camera. So it might be fine.

Based on my casual looks in the past couple of years, normal and long lenses are pretty cheap, wides are somewhat expensive. But a quick trip to keh.com will tell you best.

I used a early 6x7 for aerial photography many years ago. I found the wooden grip indispensable for handheld use.