Thanks for the information AK!
Just got my shipment confirmation email from Rachel! Whoo hoo!
My K100DS does have the shim- I had removed the factory screen to clean it a while back. I'm hoping it's stock, not some odd duck they put in to deal with a screen that wasn't focusing properly, which sounds like your specific case, AK.
If so, there are pentax repair centers in the greater Montreal area, so hoping if I need to, I'll be able to go to one and just buy the shim I need..
Can't wait! Andrew- that's exactly what I'm hoping to see: I love my MF lenses, hate the stock focus screen!