I would like to purchase a fold down rear site for my impending 1886 el 45/70 so that I can have the buchhorn site as my back up to the Lyman 66wb I have purchased...and both could be on the rifle together. Any lever buff out there could point me in the right direction ??

Marbles still makes a series of folding rear sights. They typically require a dovetail cut but if your el already came with one it will only be a matter of the dovetail fitting. Check the Brownells catalog. I think they are available there.
Frank

Thanks Frank.