After using an old ORWO FO5 film, expired perhaps 30 years ago, I tried with its newer incarnation made by Wephota. And got three strange effects:
(pictures below scanned as reflective)
- most exposed parts look like not fixed, in reflecting light they are milky grey, regardless how long in fixing bath; this is visible mostly from the base side
- there is an irregular silver frame around the edges - its width depends on how long the film was developed (in Adox R09)
- the films colour fixing bath to yellow (however without affecting fixing)
All three effects are replicable. I'm just curious...