Old phone swittches

Well, I can assure you that I do not have deep pockets, but I have 3,000 square feet of telephone switching equipment. Two main manufacturer's TRW Vidar and Stromberg Carlson DCO switches. I have been repairing these swithes for 25 years. The interesting thing about the DCO to this list is it was based on the DEC processors, 11/34 and 11//75. The DCO still incorporates the DEC Alpha CPU's, and at one time there were 1500 switches installed in the US. I know of 10 operating companies, including national carriers that are still using them. To the best of my knowedge, there is only one woking Vidar switch still operating in the US. With gov regs and technology pushing towards VoIP all of the companies will soon have the "suitcase" sized switches. Oh, and as you might guess, the MTBF is not engineered in years anymore, it is based on product life cycle.