Hello, My friend has an old Mike Matthews Freedom Amp that he just had restored. We noticed that the model he has has the protective strip of wood in the speaker baffle across the front. I attached a photo. I have searched on the internet for photos of the same amp but none of them seem to have the protective strip of wood. Do you happen to know if this was used during a particular year or why his amp has this but not others that we have seen? Any insight would be very much appreciated. Thank you very much.