The RCS was my first thought too.
There is still a gap between the acc. rails though because of the way the rails terminate into plastic.
One way to bridge the gap may be a Marx part. Marx used copper sheets with a sticky tape backing for "instant" isolated rails for triggering stuff. One or two of them could bridge the gap by being stuck over the plastic rail ends.
Just peel, and bend it over the railhead. All done.
It’s more durable than I expected. I think it could handle the shoes sliding over it. Cheap to try anyhow (Robert Grossman Co in Ohio has them)
(I actually use two sided tape for grade traction on a steep hill (+5%). A strip lasts about 3 years being run at least once a week under an E-33 and ten car coal drag for about an hour min. Mind you that's tape alone, no copper to protect it.
You could make your own too. Maybe with a cut section of normal rail vs copper if you find that silver is more appealing...?
