Hello Jim,
Sorry for this very late reply, I just saw this item today.
Helmet is a model 1843 trooper helmet, in extremely good condition and complete: the black wool ball on the houpette is hardly ever there, as is the lining which is in calf leather and very fragile. There is a very good article on these helmets (the only one existing as far as I know) in a Belgian periodical "MILITARIA BELGICA" (periodical from the national army museum, the Musée Royal de l'Armée et de l'Histoire Militaire), dating back to 1979 but very complete. Please send me contact (mail or postal adress?) and I will be very pleased to send you a copy, if not scanned then a photocopy.
First cuirasses worn from 1831 till 1843 were copied on the Imperial French cuirasses, all made by "DECHANGE A LIEGE" and with a small marking in front: the capitals GP in a rectangle, meaning in French "Gouvernement Provisoire", the first Belgian Governement being formed in the same year. Collectors should take care, these cuirasses are often sold as genuine "Imperial French".
The helmet you possess should be accompanied by a French cuirass Model 1825 with the normal French markings (Manufacture...Taille....Largeur) but with with a marking on the bottom of the "plastron": GB in a small rectangle, meaning this time "Gouvernement Belge". Very, very rare to find and hardly ever matching numbers: those cuirasses that were not sold as scratch after use, were used as decoration in military establishments such as officer's clubs etc. I have never seen a helmet marked on the back with a "3" as there were only 2 regiments: 1 in Liège (number 1) and 1 in Bruges (number 2), the latter having only existed for a couple of years. All Belgian weapons, be it swords, rifles, cuirasses, helmets, are very hard to find on the market, especially officer's items. Very nice, complete helmet, one of the better specimens that survived.
Best regards,
Johan