Found on Big Ship Salvage.com, a place that sells salvaged ship items (mainly lighting fixtures) that they have a segment from Fresnel lense from "a Great Lakes Lighthouse" of unknown origin.
Their item #P4-86.
Any lighthouse keepers wondering where part of their Fresnel lense ended up? Not sure how they got it, but they do have it. Appears to be part of a rotating lense.
Below is a link to their site:
http://www.bigshipsalvage.com/antique-p ... rettyPhoto
Pete