The "el cheapo" way to get around the rivet prices is to remove the tag by grinding off the rivet butts under the dash, then gently punch out the rivets still attached to the tag.
Use a thin layer of epoxy to attach the tag/rivet heads to the new dash.
Now you did it, we have been trying to keep that secret for decades..
And I thought I was the only one who thought of that.
BE SURE to put a piece of tape across the rivets and tag; if you don't, you'll be looking all over for two very small rivet heads.
