[MrFixr55]

Are you measuring between the antenna or ground terminal and the water pipe with a no wire from the radio connected to the pipe? is the "black" terminal jumpered to ground? Most radios of this vintage require an external antenna. There will be a tuned transformer with a relatively low primary resistance. For this radio, the listed resistance is 0.7 Ohm for 2 of the coils, 0.1 Ohm for one of them. You may see slightly higher and not be worried. If an open reading, check the band switch.

A couple of thoughts:

In the schematic, between the power plug and the power transformer primary winding, you will find 2 caps. one between each leg and the chassis. the ground lug goes to the chassis also. Since caps pass AC, there could be 60V between the floating chassis and electrical ground. Please replace these caps with safety caps. If one of these caps short, the chassis could become electrically hot.

Check between the power line and the pipes with a DVM with a 10KOhm resistor across the leads. If you don't get 120V between the Hot terminal of the power plug and the pipes, the pipes are floating. Although the house is 140some odd years old, someone may have replaced a main line with PEX or PVC. You may want to further investigate water pipe grounding, as the water main service pipe is a common binding point.

A house that old likely used threaded iron or steel pipe. If someone used an excessive amount of pipe dope and failed to tighten the pipes sufficiently to displace enough dope to have a metal to metal contact. This is not an issue with a plumbing system consisting of soldered copper tubing.