Geez, it sounds like you shortened the stock before you procured the pad. Exactly how thick do you want the pad and its spacer to be (total pad, excluding the wood)? Are you opposed to a used pad removed from another gun? Does the pad have to be red? How wide do you want it to be? Do you have a preferred screw spacing (I'm thinking 2.5" to 2.75")?

You may want to consider a leather covered pad. Would look appropriate on a DHE Repro 28.