This reel is one that was modified by a serious tournament competitor. It is the body and handle of a 1986 498 PRO with a tournament casting spool from a 1992, or so, 498 Tournament Casting reel. It also has a folding manual pickup that was not made by Mitchell. Looks like the guy that made it was way ahead of Mitchell on this one because Mitchell redesigned the 498's to incorporate folding pickups in the late 90's. I wonder if there are any more like this? The folding pickup was considered quite an improvement to the reel because every now and the, during a cast, the line would catch on the roller. When it did, you could kiss your terminal tackle goodbye. The redesign fixed the problem. 

Comment From Gerry Elliott 6-01-05: I'm positive that this was called the Shingleton having purchased one many years ago for my 498, made in England by George (?) Shingleton, he used to advertise them in the sea angling magazines around about the early 80's..not sure if he had a patent on them or not at the time.