One battalion with 6 fusilier companies and one grenadier company; 2 4 pounder guns. Nominal strength around 800 but lower in practice; for instance, in May 1758 it was 559. The two Cologne regiments, although single contingent units, were, as Kronoskaf says, "usually under strength, poorly armed and uniformed, and plagued with a high rate of desertion". The flags were very attractive, though!
In 1757 Soubise rated Wildenstein as "adequate" (Duffy) or "mediocre" (Kronoskaf).
Wildenstein missed Rossbach. In 1758-9 it was attached to Zweibrücken's Corps and was probably at Korbitz on September 21st. In 1760 it was at Strehla. In March 1761 its luck finally ran out and, while trying to guard the Saale river crossing at Schwarza, it, along with Mengersen Infantry, was captured by a roving Prussian corps.
And this was possibly the uniform in 1756 (Kronoskaf favours the coat with red facings):