I just installed an OER dash in my '69 and used the original clips. You are correct that they fit a little loose when you clip them to the dash, but they definitely do the job once you install the pad onto the metal dash structure. I didn't think it was a big deal because the clip mounting areas on my original dash were in good condition and the clips fit loosely on the original dash too.
I wouldn't recommend using silicone. The clips hold the pad close to the metal. If the silicone globs are too big, the pad won't rest against the metal.
Thought I would add - the OER repro 69 dash is pretty good. The fit was excellent, but the finish could use more detail. The molded grain and stitching was not as pronounced as my original. It's a great piece for a rodder, but definitely not good enough for a resto freak.
[This message has been edited by gheatly (edited 04-09-2002).]