With bulk lots (never for only one roll) of old films, I do a clip test with 10-15 centimeters of film and process it in Kodak D-76 1+1 for 10 minutes a 24C or whatever your usual developer is. No need to vary the time. This (almost) never fails.
Results will speak for themselves. If the film is recent, it will (or may) have data on the edge, and you will also see how fogged the film may be.
When you see the results, I recommend the following. Throw out the rest of the film and reload the FILCA with fresh film, and then go out and shoot some nice images, full knowing your results will be usable.
Even better, turf it out now. Save yourself the trouble of processing it. Doing one roll really isn't worth the time and effort you will put into it.
You can save the Leica-cut leader for multiple future reloads or as a template to cut your own from short film lengths you can then tape to your loaded film. Again, is this worth the effort? For me, no.
FYI, my 200 rupiahs' worth of "useful" advice...
