From what I know it is very difficult to ascertain whether or not a cap of the style you describe was worn during the war or not. A review of period images and extant examples quickly indicate that the combination of sloping visor and chasseur style body would have been very much the exception rather than the rule. However, that is not to say that somewhere, at some time during the war someone didn't combine the sloping visor of one of the Federal style caps (wheel cap, or models 1859/1861) with the body of a chasseur style cap. Wear it and tell anyone who cares to ask that your mother made it for you.
While a great deal of research lays behind the impression of many a reenactor or unit, the usage of an item amongst reenactors as a body does not always mirror the proportion of an item's use by Civil War soldiers. That being said, if you do see someone wearing a cap like yours ask them why they do. You may uncover a vast repository of knowledge and an even better answer than this!
All the best,
To Join the Company of Military Historians click here