A gear broke on one of my Roomba. I stumbled upon this site while looking for parts and am grateful for it. The service was exceptional. Items arrived as expected but did not fit. After speaking to the website, it was discovered that my Roomba has parts that differ from the model number listed. I have several Roomba and this one was offered at a reduced price by irobot when one of the other units failed beyond repair. The replacement appears to have been assembled from parts from multiple…