Euro Cut blankets, etc. almost always come in 3″ increment sizing, such as 69-72-75-78-81-84-87.
76″ blankets, etc. are normally part of 2″ increment American sizing system, such as 68-70-72-74-76-78-80-82-84-86-88.
I suspect you will have some trouble trying to find a Euro Cut 76″ flysheet, or anything else.
How did you measure your horse? Euro Cut blankets are measured from the center of the chest to the outside edge of one back leg, with the horse standing square. The 2″ increment sized blankets are measured from the center of the chest to the butt crack. Because they are measured differently, the 3 sizes that occur in both systems (70-78-84) will not be the same size blanket in both systems, with the Euro Cut blankets typically being bigger than the 2″ increment sized blankets, particularly with reference to the 3 sizes that exist in both systems. Many 75″ Euro Cut blankets will be approximately the same size as a 76″ 2″ increment sized blanket. However, typically the chest is larger on the Euro Cut blankets, so while a 75″ Euro Cut blanket might fit a chunkier horse that usually wears a 76″, such as a warm blood or AQHA, the chest may be too big on a narrower horse, such as an Arabian or a TB. Which breed is your horse and is he/she typical for that breed?
I will check what I have in stock and see if I have anything that might fit your horse.