In 1826, the 'Silistra Cavalry Regiment' was formed [1], as part of the general reorganization of that year, and was raised in Silistria province (the Danube Delta), and made up of Turks, Tatars and Christians in equal proportions. The latter were a mixture of Zaporozhain Cossacks who had fled Russian rule and been allowed to settle in the region. In 1826, the Regiment/Brigade was organised into two battalions:

• Lancer armed (unit made-up from Cossack recruits); and 
• Dragoon Battalion.

A new uniform for the 1826 regiment, was issued to the men:

• Vests: This could be referring to the sleeveless over-coat-vest, which was fitted with hanging sleeves/wings that are commonly seen in Ottoman, and Cossack uniforms throughout this period.
• Short jacket: Likely to be, the standard jersey issued to all New Model Army soldiers in 1826, and afterwoods. 
• Oriental breeches. 
• Black riding boots.

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[1] Levy, Avigdor. 1982 Formalization of Cossack Service Under Ottoman Rule. Gunther E. Rothenberg et al. (Ed.). East Central European Society and War. New York: Columbia University Press.