Zonie's comments are spot on, as are those of VaManuf...
George's book, Battle Weapons of the Revolution, is just about out of print but a new edition is in the works. Also... for the best photography of the best extant examples of the Land Pattern Muskets get "The Brown Bess" by Erick Goldstein and Stuart Mowbray. (you can get it on Amazon or from the publisher, Mowbray Publishing) The Goldstein & Mowbray book is all high quality color photographs with most of the guns coming from the Colonial Williamsburg collection. The most comprehensive book available is DeWitt Bailey's "Small Arms of the British Forces in America, 1664-1815. There is also "Redcoat & Brown Bess" by the late Anthony Darling, though that is fairly dated now and has been superseded by DeWitt Bailey's book and the Goldstein & Mowbray book.
However, you may just find that the reproduction does not correspond exactly to any known pattern. This is partly because there are a huge number of buggered up, bad "restorations" out there being accepted as original. Don't let anyone tell you they were constantly rebuilding these and that all sorts of minor differences existed etc... The British Ordnance was very demanding in quality and, within the tolerances of 18th century technology, they demanded, and got, a very great deal of uniformity.
As to the gun itself... it is clunky and there is too much wood. To answer your question as to why... I very much doubt anyone involved had a good Long Land Pattern to compare it to... they probably relied on pictures and may have made the mistake of relying on someone else's bad restoration or even a reproduction. The ability to actually "see" the differences is more artistic than mechanical - some are so subtle that without a good example of the real thing at hand, or lots of years looking at original examples, they are nearly invisible to the average person. That stock is much too thick and the lock panels are much too big. Those criticisms are accurate but if you're happy with the gun thats all that should matter to you... With some careful work it could probably be altered to look much more like an original if thats important to you.
As to the wooden ramrod version, yes they are rare and the internet is absolutely worthless as a source of information on this subject. If you really want to know, buy the books. I owned one 25 years ago, a Pattern 1730 converted from wooden to iron ramrod (what DeWitt Bailey calls the 1730/42).