I like that strap, I know that it is in unusually great condition but the buckles and end fittings look excellent to me. As far as the M91 ends being chunky. Look on the chin strap thread I started and you will see some brass examples which are the same. Your buckles are also the more delicate round edged ones that we see on original M95 leather straps. In addition, that is a very nice helme, in excellent condition. Congratulations.