If you want to continue using your seven Pentax lenses, your best option would be to upgrade to a better Pentax camera.
There are mechanical adapters that allow Pentax K-mount lenses to be the correct distance from the sensor so that infinity focus is possible with Canon EF mount cameras. But you're going to give up almost all automation: autofocus and any ...
There are three likely causes of this kind of mark on the film.
First, bromide drag from insufficient agitation. Second, surge marks from excessive agitation. Neither one is very likely for film developed by a commercial lab, though they're certainly a possibility.
The third possibility is a light leak -- not in the camera, but in the cassette, ...
I'm pretty sure it's not Pentax K (PK) mount. It might be Nikon F (NF) mount.
All of the control and communication linkages are missing, but the page you link seems to indicate this is normal for that lens.
The alignment dot has the same position as NF.
The locking slots are located between the flanges, like NF. The slot would adjacent to one of the ...
Really fascinating question, I felt compelled to look into it to find out!
I'd say there are 3 possible answers to this:
The most likely answer: Pentax engraved the first owners name (Masaaki Nakagawa in this case) on the camera before shipping it to them.
Evidence suggests that Pentax would sometimes engrave the owners name on a new camera before shipping ...
This article explicitly discusses the differences between the 2. Whether or not those differences are worth any variation in price is entirely up to you.
Enter the K-1 Mark II, a new DSLR which is almost identical to its predecessor, but with the inclusion of several new elements: