Looks like you have a decent, almost flat area to affix the replacement lights to. Maybe take a close-up of each area if you can and repost it. If you could separate the replacement marker light post from the excess material maybe using a Dremel tool if you have one while keeping the part in a vise, I would do it that way, if that makes sense. I would then carefully "butter" the replacement marker post base with the JB Weld and butter the flat area it is being affixed to...use a toothpick to carefully remove any excess epoxy and/or contour the shape before it hardens.
Send pictures, if you can, when done.
Tom
