I've had the last two pop or nearly pop the handle (heard creaking on the last one, so i took the riser off before it popped). My solution (recommended by folks here) was 1/8" wood laminations in place of one thick riser piece. Worked like a charm
I do want to try the leather like you have done, but just don't have any thick enough. Looks good, get'r finished up so we can ogle!