In the photos, the gonk, in order, is f2.5, f4 and f8. The water can is f2.5 and f8. With the can at f2.5, it seems like the bokeh wants to start getting swirly like a Helios 44 or a Carl Zeiss Biotar.
MC Soligor Wide Angle 28mm f/2.5 Prime Lens Vintage Manual Focus - Working
Soligor 28mm F2.8 Lens - Made in Japan - Free P&P
Soligor 28mm f2.8 WA Lens PK
Soligor C/D Wide-Auto 28mm f/2.8 Wide Angle Prime SLR Camera Lens 2808307
SOLIGOR 200MM F4.5 TELEPHOTO LENS M42 MOUNT CAPS INC, BOXED. GLASS IS VERY GOOD
Soligor 300mm f/5.6 Prime Telephoto Lens - Soligor T4 Interchangeable Mount