Thank you! I am not sure I understand this completely, but the main question is: does this add to the color of the sound, or only adds pitch variation?
Depends on the combination of effects.
As I attended a solo concert he used sound changing effects like modulated delay, chorus, phaser/flanger etc. but also sound neutral freezed delay lines for accompaniment and some reverb for room simulation.
My experience with most musicians is that they don’t like to talk about technical stuff but rather about music (if they do like to talk at all).
And they don’t like to get copied but rather want other musicians to find/do their own thing.
Sometimes you might get a more general hint, but almost never a complete description that you can duplicate.
I don’t think it is important now which exact device model was used in much earlier years (except for history). There are so many effects with a lot of possible parametrization now that it doesn’t make sense to chase for rare old devices (that may break down rather earlier than later).
For trying things out there are so many rather cheap but still flexible devices available now (even very cheap not too old used devices) that it makes sense to get something cheap and experiment with single effects first and then try find good combinations.
It is time consuming, but if you use effects you should know what you use and why.
And if your device of choice is no longer available or reliable, you would be able to transfer the principle to actually available device and know what the need to be able to do.