The array of Austrian military longarms is quite confusing. However, as I recall, all Lorenze models were rifles (or at least rifled muskets), as opposed to a smoothbore musket. The Lorenze was a very commonly used longarm in the CW, by both the North and the South. It was about the most commonly used behind the U.S. military models and the British Enfield models. There were other Austrian models that were true muskets, that were extensively used in the CW...mainly the Model 1842. (Some Model 1842's were rifled-muskets.) There were approximately 100,000 of the Model 1842's used by each side (totaling approx. 200,000 used in the CW).
The Lorenze models bring more money than most of the other Austrian weapons. You really need to find a copy of Edwards'"Civil War Guns" to identify exactly which model you are being offered. A lot of dealers call all Austrian percussion models "Lorenze", which is not correct. But if it is either a Lorenze or a Model 1842, it would at least be of the sort used extensively in the CW, even if it may not have actually seen service here.
[Note, some Union used Austrian weapons have a plate in the shape of a shield on them. These are those bought by Boker. Some C.S. used are marked "C.S." on the barrel and/or the buttplate tang. These seem to have been those transhipped to Texas. A very few C.S. used have engraved numbers on the buttplate. These apparantly were delivered to Wilmington.]