Here is the finished bearskin compared to a 1778 drawing of a grenadier by Philip James de Loutherbourg. The height difference is apparent, as is the grenadier's badge at center back. The cord pattern on the 7th Foot cap is completely conjectural, but is similar to surviving examples. Insanely talented Alexa embroidered the Regiment's badge on the madder wool bag. Perhaps some bear hair gel is in order.
Another de Loutherbourg comparison makes the cap height difference clear between grenadiers and fusiliers. Sadly, all the 7th's dress headgear was captured with their colors and a year's worth of clothing at Fort Chambly in October of 1775. Simple cocked hats were the order of the day after that.