I have the 90 mm David grieve musket that goes with my Minden figure but 1759. He also has all the equipment which is suitable for that period, haversack, waterbottle, sword etc. not up to speed if musket is ok but I have the original master without hand attached, David added the hand to a cast for production.
PM me if any parts are of use the figure is on the CGS web page under 90mm in the shop section if you want to look. The grenadier drummer parts may also be of use
Best wishes