I did the same, replacing some timers. Sure the original designer of them at Siemens in the 1960's did not think they would still be running nearly a half century later. The only reason I replaced them was the contacts on the relays finally were worn out, and had gone intermittent. The power supply of the timers was fine, even if the capacitors are tired, the resistors are weeping wax and you no longer can get unijunction transistors easily. The actual Siemens relay used inside is still made, but to get them was more expensive than the replacement Omron timers and the sockets, plus the original timers use a not very common socket, which has soldered contacts and is not DIN compatible.