Buying another camera body just puts you in the same Vegas dice-roll on ebay. I would send the camera body to Eric Hendrickson of Pentax Camera Service.
For FREE he will evaluate the condition of the camera, identify repairs necessary to bring it back to as-new operating condition and quote you a firm price to make necessary repairs. You will then have a warranteed camera that will last for 20 years.
His charge for a
Clean,
Lubricate,
Adjust is less usually than $60 - about the price of another trial body.
If you refuse his quote he will send you the camera back FREE OF CHARGE. Your total risk is about $10 - the cost of Priority Mail to Sharps Chapel (Knoxville) Tennessee.
Many on this board swear by Eric's work for all thier film cameras and lenses. I have personally had more than ten camera bodies clean and/or repaired by Eric since 2004. Here is a link to his website to see for yourself what he does and what he charges. Click all 5 links on the right to read the whole story.
Home for Pentax Camera Service
FWIW, I have no financial interest or other reason to recommend Eric - but the tradition on this Forum is to offer referral services and testimonials for those who have given great Pentax service for many years.
Good luck - that is a wonderful camera.