67-9 Dart/Barracuda Console mounted tach base

I have been looking for this part as well. In my searching I think I have discovered that 67, 68 might be different than 69 ?? Why I think this is because 67, 68 console has a trough or strip (not sure what to call it) running down the full length in the centre of the console. The spacer has two locators (nubs or bumps) on the bottom that sit in this trough. 69 console is smooth or flat which doesn't allow this piece to sit flush. It will rock back and forth. Now maybe my only choice would be to file the nubs off. Any thoughts ????
Thanks

Very likely correct.