[vinnie]

That does clear some things up! Re-looking at the pictures confirms that the camo is the same. Thank you for adding the pictures, Martin! This confirms Prien's thought that black 5 and black 20 were the same aircraft, i.e. Werk Nr. 15429. In the back of the last picture one can recognize black 10, Lt. Joachim Göhres G-6/R-6 (Werk Nr. 15458).
To summarize: From july till 8 October 1943 Miksch flew in black 5. His rudder shows about 38 victories, the number of kills he had at 18.7.1943. On 8 October 1943 he crashlanded, and after that day his plane was renumbered 'black 20'. When flying in his 'new' black 20, his rudder shows the same amount of victories, while at that time his total score was 42 victories? He then probably used black 20 until he crashed on the 3rd of November. After that, Me-109 G-6 black 13 became his plane.