Replacing Power Cord on Vintage Tube Radio

I am fixing up an old tube radio for a relative. It is a table radio that is approximately 41 years old, which has been taken well care of. Overall it is in great condition.

The insulation on the power cord is cracking & crumbling. Thereofre I need to replace it.

The original power cord looks to be standard "lamp cord."

Though I cannot find any specifications, I cannot imagine that the amplifier section is large or draws a lot of current.

The tubes that this radio uses (one of each) are:
12AV6, 35W4, 12BE6, 12BA6, 50C5.

Given this information, is there any reason that a new 18 gauge power cord wouldn't be adequate for up to an 8' length?

If that gauge has worked without failure for 41 years, it's replacement should be just fine, and if your really worried about it, you could go with 16 guage for overkill.
Ya, why not give it a bit of an upgrade? I would go with 16 gauge if not some high end wire, like silver plated copper wire. Have fun.