Rifa made top-notch capacitors back in the day, but that day was, indeed, 30+ years ago. Axial elkos are getting harder to find, but there should still be sufficient stock at the usual legit distributors like Farnell, RS, Digikey, etc.
Not sure of your skill/experience level with electronics, but usually the value of elkos isn't too critical, so it would be perfectly reasonable to replace all capacitors of, say, 470uF to 1000uF (aka 1mF) with 1000uF units. In other words, don't go searching too hard for that 680uF/16V capacitor...