While the name looks Romanian on the first viewing, more common form would be Petrescu. On the other hand, with correct accents and translation 'Jiří Petrů' returns lot of hits (contemporary)
https://en.wikipedia.org/wiki/Czechoslovak_Air_Force. The CSAf definitely did have up to 500 S-199 and also about 40 of the leftover about Bf-109 after the war.
For a Czechoslovak citizen to have flown the Stuka and be capable of defecting with a S-199/Bf-109, chased by Russian fighters - that would pre-date the V-E day. An educative and thrilling account of what that plane was like:
https://www.airspacemag.com/airspace...ife-180972958/ (final paragraph: 'treacherous attributes')
During the war times however, the CSAf was decommissioned. As much as 1500 of their airmen escaped the country via underground links.
After the Communist take-over of 1948 most of the wartime heroes were heavily persecuted, similar to other countries. Probably except Poland where they got killed the first time Soviets arrived. Escape attempts were common, the succesful airborne ones not really that many but still spectacular.
https://fcafa.com/2012/04/21/escape-from-prague/
https://fcafa.com/2011/03/12/they-flew-to-exile-1950/
Those who made it are considered heroes by today's Czech iconography and there is no public trace of a successful run onboard S-199 / Bf-109. / C-10. Unless he served with Luftwaffe, neither the proxy Slovak Air Weapons (SVZ) seem to have operated Stukas despite the localized production. Relevant contacts:
VHU PRAHA
The origin of his story is probably either lost or even somewhat built deep down the memory lane.
megan Slovenia / Slovakia.
Prijazna hvala!
EDIT: Found this online, Google translate hits the important points: ttps://www.idnes.cz/technet/vojenstvi/ceskoslovenske-letectvo-stihaci-letadlo-avia-s-199.A200116_174150_vojenstvi_erp