Hi,
Welcome to the forum. This is a great community of skilled and knowledgeable gun makers. The link below shows a pretty representative English fowler from 1765-1775:
http://americanlongrifles.org/forum/index.php?topic=44567.0Note the small trigger guard. I have never seen a real English fowler with a guard like the large acorn finial guard sold by TOW. The bow is much too large, the shape of the bow is wrong, and the finial is ugly. The acorn on my fowler is correct and looks much nicer. Typically, English fowlers had versions of the flaming urn finial from 1730s-1760s, then acorn from 1760s-1780s, then pineapple 1780s-1840 or so. Round-faced locks dominated on all levels of quality during the first half of the 18th century, after 1760 or so, flat faced locks were almost universal on better quality guns while round-faced locks were usually on livery, military, and low end export guns. There were always exceptions to those trends and you should be able to find alternatives to the acorn such as floral finials. The tough part about English fowlers is the stock architecture. It is distinctive, particularly around the lock area. Fore stocks are egg shell thin and that is no exaggeration.
I consider Mike Brooks, James Rogers, Taylor Sapergia, Rich Pierce, and Ed Wenger my "go to guys" when it comes to making English sporting guns. Good luck.
dave