I am going through my wiring harness post paint and most of my black cloth tape disintegrated. Is there a source for replacing it?

It is Tesa tape. You can buy it pretty cheaply on ebay or 914Rubber carries it.

There are different widths of the Tesa tape. Look for the smaller widths...something like 1/4" from what I remember.

I just cut down some hockey tape, it looks like the same cloth tape. $2 a roll.

Tangerine Racing has the good stuff.

Tesa 51608, 25m x 19mm adhesive wiring cloth tape?
Click to view attachment

We stock the tape in correct 12mm width

180’ roll
Make sure when you compare you check length. There are cheaper at 60’, but you will need 2 and 1/2 rolls.
https://914rubber.com/wiring-harness-tape-1

As well as the vinyl tab material for the metal tabs by the ft.
As shown