Here is a bit of backround, I work supporting a rather large collection premier 2554 wall phone's (200+) and on the back of the phone is a UL label, howver the Handset it not the "Stock standard" handset it is a Walker W13-500 (which is a Armoured handset cord) does changing that modify the UL Listing ? Or does the Fact that they took off/broke the 523D slider on the phone when putting them up change anything other then the obvious pain it is to determine where the problem is when there is One