Uhlans and lance circa 1760 -Anne Brown Military Collection

 Salvete Omnes,

a quick post - the Anne S.K. Brown Military Collection (Brown Digital Repository. Brown University Library) contains a vast number of military-related images from various periods.
In this 13 print collection by Johann Georg Hertel and Carl August Grossman we can 'corral' 5 prints that may show the Polish cavalrymen (Lithuanian Tatars et al) in the service of the -Polish-Saxon kings up until 1763 (when Augustus III died and uhlan regiments were recalled). The date - 1765 - is approximately one year after for these cavalry units to have been returned to Polish-Lithuanian Commonwealth, where they were re-incorporated into the army.
these three are the most telling as to a hypothesis that they show Polish uhlans from the Saxon royal army:

So in these three prints we can see kurtka, kontusz, katanka, szarawary, dzida (lance),and old Polish customs of head shaving and bowing as a sign of respect - kronoskaf side dedicated to the 7 Years War has two of these lance-bearing regiments described and reconstructed via illustrations - here and here.  

Nota bene according to the  sources the first time these Polish-Lithuanian Tatar lance cavalry banner were called uhlan cavalry occured in 1735. Upon capitulation of the Saxon army at Pirna in 1754 our king had three uhlan regiments - Rudnicki (fully Czymbaj Murza Rudnicki), Renard (who replaced Bronikowski) and Wilczewski - in Polish Crown territory.  In 1756 two regiments - Rudnicki and Renard - marched to join the Saxon corps in the Hapsburg Austrian army (they participated in the famous raid on Berlin under general Hadik) , while Wilczewski's regiment stayed in Poland. During the war additional uhlan regiment was created and by the winter 1762 there were four  royal uhlan regiments - the commander of one, count Renard, returned with the Saxon royal troops to Saxony, and those four uhlan regiments were led by four commanders - Jozef Bielak, Mustafa Korycki, Jozef Chojecki and Ahmed Skirmott.*
Thus in the early Spring of 1763 the story of Polish-Lithuanian uhlans on the Saxon royal kings service ended, and they rejoined the Polish-Lithuanian armies.

valete

*article by Grzegorz Szymborski, Jak Tatarzy ulanow stworzyli-historia polskiej fromacji wojskowej - many thanks Grzegorz.
Borawski Piotr, Tatarzy w dawnej Rzeczpospolitej, Warszawa 1986

Borawski&Dubinski, Tatarzy polscy. Dzieje , obrzedy, legendy, Warszawa 1986

 Ciesielski Tomasz, Armia koronna w czasach Augusta III, Warszawa 2009

Kryczynski Stanislaw, Tatarzy Litewscy, Rocznik Tatarski, vol.III, 1938

Trabski Maciej, Pulki przedniej strazy wojska koronnego w latach 1768-94.  Chorzow 2012