Every knob and tube home Iâ€™ve seen has needed upgrading in some way to add additional electrical service to meet the needs of todayâ€™s homeowners. Additionally, many homes have replaced the original fuse panels with modern electrical panels with breakers instead of fuses.
Oakland is in a Zone 4 seismic area and homes built from circa 50's and older can be very vunerable to shifting off of their foundations and collapsing on the ground resulting in a total loss in most cases. Good luck.
Knob and Tube is not the end all be all and in fact I have seen it work for many homes. Often times, you will see it with conjunction to an updated electrical system. Before purchase, you want to make sure you get an electrical inspection and a home inspection. Here is an article written by a local home inspector that you may find useful:
I have knob and tube in my 1914 bungalow, the knob and tube looks fine itâ€™s the additions from other electricians over the past 99 years that have made it a concern. At least that is what my electrician told me.
But if you are concerned, then for your own peace and mind, you may want to upgrade to your satisfaction.