This list was compiled and kindly provided by noted blogger Matt Golding for the benefit of those determined to acquire a 19th century army or two. Non web based companies have not been included. (last updated: 23 April 2018)
Askari Miniatures (25mm) Intended as French colonial figures there are a number of models suitable for the Crimea, Risorgimento, and Franco Prussian Wars.
Aude Miniatures (15-20mm) Interesting range of predominantly 1848 Risorgimento figures (plus Garibaldini in 20mm).
Eureka (15/18mm - 25mm) Crimean war and other smaller ranges in 15/18mm Small, infantry only, 1864 range for Second Schleswig Holstein War.
FreiKorps 15s (15mm) Extensive coverage of 19th Century conflicts in 15mm. If you cannot find it anywhere else then it will probably be in their catalogue.
Grenadier Productions (15/18mm) Not strictly European, but a large range of figures covering the Wars of Liberation in South America following the Napoleonic wars.
Heroics and Ros (6mm) The original 6mm figure range; wide range of figures including Napoleonic and Franco-Prussian War that can be used for the Austro-Prussian War and Risorgimento. Not compatible with Baccus figures.