P3D Repairing vintage slides

[Linda Nygren <lnygren@xxxxxxx>]

I recently acquired a lot of vintage (1948-51) glass-mounted Realist
format slides that are falling apart, but quite a number of them would
be worth a little effort in cleaning them up and remounting. (Mostly
scenics, in areas such as Bryce Canyon, Zion, Yosemite, Banff and Jasper
etc.)  Mainly the old red cellophane type tape is crumbly; some slides
were taped with a cloth type red or black tape which is coming loose
somewhat but at least not leaving red debris everywhere. The "dirt" on
the slides appear to be on the glass, not the film.

My main question is whether a good red tape is available for this
purpose, to maintain closer to the original appearance, or even black. I
am more familiar with silver mylar tape although I do not actually have
any. Other advice also welcome, including best way to clean glass etc.
-Linda