If I had to make that relay work, I might try spinning some more magnet wire on the solenoid to bring up its DC resistance or, stretching the spring a tiny bit to reduce its mechanical resistance. In one case, I've even swapped the solenoid from the original relay to the replacement, in order to keep it compatible with the circuit. I wouldn't expect changing the polarity to make any difference here.That is the one I tried Nomadradio and all it wanted to do was chatter, didn't work well unless I cranked up the deadkey View attachment 70684