Nothing beats the basics for functionality on breast collar connector straps…start out with 10 oz Hermann Oak (case and compress to 8.5 oz), hand sew stainless #150 buckles on with waxed linen, rub edges, lay a crease line on the edge, dry, apply warmed neatsfoot oil, then lastly a heavy load of Ray Holes Saddle butter. These should out last me. I just love making this kind of stuff.