Someone used to make a mount that sandwiched across the front of the trigger guard, for lights and lasers. It used two screws to create a friction mount. I remember seeing them around '89 or '90. Kind of like this...
But I don't remember who made it, now.
Call Streamlight, I bet they have or use to have a mount that'd work.
EDIT: Changed the pic to something more relevant. I'm pretty sure that's an old Surefire light. If that's their light, they probably know where the mount came from (image borrowed from the 1911forum.com).
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