There were also two styles (manufacturers) of belts. One used metal buckle housings and the other used plastic. I don't know if the sleeves were different between them.
Yes, that's what's shown in the two sleeve pics. Deluxe on left, being chrome or colour-matched backing, of the boxy plastic style on the right, as per ebay ad. These are often matched to the Irwin belt selts and is moulded into the sleeve near the bottom opening.
JJ, do you mean compared to the stock '76 belt with retractor at base next to seat? Don't they still have something like these stalk at console, albeit updated style?