Also lt. meines Wissen und auch meinen Quellen is das IR 31 ein reguläres ungarisches Regiment:
Generell kann man sagen, deutsche Regiment hat bis 1809 den Raubenhelm und danach den Tschako, bei den Ungarn wars genau anders herum. NatĂĽrlich gabs ausnahmen und man muss davon ausgehen das nicht sofort 1810 alle Regimenter mit dem neuen Zeug ausgestattet waren. Das muss man sich dann im Detail ansehen
Hier einige Infos zur Geschichte und zur Uniform des IR 31
K.K. IR 31 – FML Johann Benjowski (Benjovszky) von Benjov – 3 battalions
der SiebenbĂĽrger Regiment

Recruitment: 1 Depot comp. at Ofen, Div. baron Karl Weidenfeld, Brig. baron András von Szörenyibefore
Aspern: Assigned to the army of Germany, VI Corps FM von Hiller, Div. Jellacich then was in the Div. Vincent, Brig. Hofmeister.
At Abensberg 2 comp. were with the Détachement Rittmeister Spannagel, other 2 comp. with the Avant-garde brigade GM Armand von Nordmann, the regiment with Brigade GM Hoffmeister von Hoffeneck, Division FML comte Friedrich baron von Kottulinsky. During the retreat it returned in the Div. FML Vincent in the rearguard fighting at Rohr and finally at Landshut (April 21). At Landshut the 1st battalion was detached from the rear-guard of baron Carl Vincent. During the two battles the regiment lost 41 dead, 60 wounded and 345 prisoners. At Neumarkt it was in the 3rd Column (Left), Brig. GM Josef Hofmeister von Hoffenegg.
At Ebelsberg the Brig. Hofmeister was always under Div. Vincent but in a rearguard sector led together with the Div. FML Emmanuel von Schustekh. Vincent deployed the Brig. Hofmeister with the Chevaulegers at Klein-MĂĽnchen in order to support the extreme rearguard retreating under the French fire (Brig. Bianchi). The brigade Hofmeister found the new positions full of all sort of carriages and material. So was forced to deploy north of the village. They were attacked by the French cavalry and retreated till the bridge (Traun river) repulsing the advancing enemies with bravery. However when the French guns began to bombard the situation becam critical and they withdrew on the opposite river bank. There the regiment lost around 598 men in total, of which, it was referred, 189 sunk in the cold river waters.
It followed the retreat in Austria, the passage of Danube at Mautern (May

and the rest at Grafenwörth camp.The regiment was reorganized in the Division GM baron Carl Vincent under the provisional brigade oberst baron Franz Splényi de Miháldy.
at Aspern: Brig. Hoffmeister, Div. Vincent, VI Corps with 3 battalions (1130 men). The 1st battalion was ordered to do a flank attack against the Kirchhof positions (Aspern), under the command of General Staff-Oberleutnant Josef von Ehrenstein. The rest of the regiment supported the assault and lost, in total: 38 dead, 166 wounded, 5 prisoners.
between Aspern and Wagram: After the battle the weak 1st battalion was disbanded and the regiment remained only with the 2nd and 3rd battalions with the new colonel Stefan Hirsch. Meiller and Bánffy left the regiment and the new oberstleutnant was Mathias Ivanka. On June 22, however, Hirsch returned to IR 32, and the new colonel was Paul Maria Joseph Senitzer. Ivanka retreated from service and the new oberstleutnant was Josef Odelga (majors Johann Mécsey prisoner, Baumgartten and Déak).
at Wagram: the 2 battalions were with Brig. baron Franz Splényi de Miháldy, Div. FML baron Kottulinsky, VI corps Klenau. They followed the retreat of the VI Corps losing: 9 dead, 54 prisoners. During the retreat they fought at Korneuburg (3 dead, 23 wounded and 87 prisoners), Stockerau (1 dead and 10 wounded). Always acting as rearguard it was ordered by GM Mariássy to stop at Hollabrunn, together with the twin regiment Splényi and some companies of IR 60. They lost there (July 10) 46 dead and 543 wounded. It was not at Znaim.
(Quellehttp://www.napoleon-series.org/military/organization/Austria/ArmyStudy/c_AustrianArmyIntro.html)