Messerschmitt Bf.109E - Slovak users

Between 1st July and 5th September 1942 the relatively recently created Slovak Air Force (created back in 1939) received two Bf.109E-2, one E-3, five E-4 and four E-7 instead of the initial 12 Bf.109E-7 promised. The aircrafts were second-hand and well-worn that had seen combat both in France, the Battle of Britain and even in North Africa. Some of then were even crashed and repaired several times, however, as the Bf.109E by that year had already been widely replaced by the Bf.109F as Luftwaffe's frontline fighter, the addition of those Bf.109E represented a significal update for the inventory of the Slovak Air Force.
The pilots that soon would fly them, were trained in Denmark with additional training made in Piestany, the airfield of Bratislava, the capital city of Slovakia.
All of them were assigned to 13. Letka (13th Squadron) and assigned to JG 52 to be deployed in the Eastern Front and on 14th October 1942 they departed for the frontlines.
They were rebased to the town of Maikop, at the foot of the Caucasus 70Km (44 milles) south-east of Krasnodar from were they operated in various 'free-hunting' mission where they shot down various Soviet Aircrafts, mainly outdated Polikarpov I-153. The following months they performed mainly free-hunting missions and escort missions for the German bombers. However, due to the shortage of aircraft, by the end of November, they only could field three combat-worthy Emils.
It was agreed to replace the Bf.109E by the Bf.109F in December 1942 but as the training had to be made in parallel, many of the Emils remained at the frontlines in Maikop until 3rd January 1943 when they were rebased to Krasnodar, in the Kuban region. It wasn't until March 1943 that the unit wasn't fully converted to the Bf.109F.
The Emils, however, weren't withdrawn from active service and, as the war developed, they were assigned to the defence of their homeland's skies and later, when Slovakia uprised in late August 1944, the Emils composed the backbone of the Combined Squadron of the Slovak Insurgent Air Force. Apparently, after the uprising was uppeased, the Slovak Air Force ceased to exist.

Sources:
1. https://en.wikipedia.org/wiki/Messerschmitt_Bf_109_operational_history
2. Osprey - Aircraf of the Aces 58 - Slovakian and Bulgarian Aces of World War 2
3. Salamander Books - The Complete Book of Fighters