Hello, from Russia... That's VERY interesting, as You know, better than me, that the Yak-7 was extremely similar to the Yak-1M that Lidya Litvyak flew usualLY, even that day... So, it could be that Hartmann was the victor of Litvyak... but if I understood well, Hartmann was from II.JG 52, while, according to the "table kills" of our friend RusoArgentino, she encountered, that day, pilots from I.JG 52. 
 
 1.08.1943 73 GIAP Yak-1b "White 23" Bf.109G-6 W.Nr.15852 Unknown (50% dam) 2./JG 52[57][58] 
 1.08.1943 73 GIAP Yak-1b "White 23" Bf.109G-6 W.Nr.20423 Hans-Jörg Merkle - KIA (30-kills ace) 1./JG 52[59][60] 

You know if there is a biography, even in German, more specific than those of Toliver and Kurovsky?
Cpaccibo!