@MdM69,
Hi only just started but these my answers
12d. Barrel strip: sta?? STAVE
27a. Jacket slits: ?e?ts VENTS
56d. Cyclists' qualifying heat: re?e???ge REPECHAGE
80a. Buckle pin: ???p? CHAPE
143a. Thin film of ice: ?e?g?as VERGLAS
93a. Early Iranians: ?ede? MEDES
hope that helps, good luck sandray