May I suggest Dennis Potter also for your consideration. I agree Doug Mann does a great job on leather covered pads.
As to wooden plugs. I used to use the wooden plug method too. I found StockCap Corp. out of St. Louis about seven years ago. They make rubber plugs in many different sizes. I now use a 7/16" cutter to make the hole in the pad and a .350 plug. Using leather in the 1.5-2 oz weight(.022-.032 diameter) gives a good fit when the leather is put in the hole and over the plug. I made molds for forming the leather around the plugs which help keep sizing accurate.
