OK, I got the whole lot for $80 (he was very flexible), and here's what it all is:
Lenses:
Vivitar Series 1 90mm f/2.5 Macro lens for Pentax w/Kalt UV filter
Vivitar Series 1 90mm f/2.5 Macro adapter lens (has a tripod mount--what does this thing do?)
Pentax M 50mm f/1.7 lens
Tamron MC Tele Converter 2X for Pentax
Minolta 135mm f/2.8 lens
Lentar 90-230mm f/4.5 lens, M42(?) w/Minolta mount screwed onto it and w/Hoya UV filter
Pentavision Super Wide AF Macro 0.42X lens (not pictured below)
Cameras:
Pentax MX camera
Yashica Lynx-14 with 45mm f/1.4 lens
Flashes:
Vivitar Thyristor 265
Vivitar Wide Angle Attachment V-265
Sunset TR-100
Extras:
PC cable
A whole bunch of lens cases
Old padded camera bag
A bunch of random front and end caps
Some Minolta manuals
Two camera straps
An old key
Here's what it all looks like, minus the lens cases and one of the lenses:
Kudos to ryan s, ChrisN and others for making correct guesses! You guys know your stuff!!