Help please - build year and model?

[Drillit]

Hi all,

My name is Derek - born in South Africa but now I live in Australia.

I have 5 Kreidlers - from fairly complete to just a frame/engine. I am looking to import these to Australia and I need to provide a year of manufacture. I only know one from the registration paper.

Can someone please help to point me in the correct direction?

#1frame#5125792 k54/505
#2frame#5141115 k54/50(4?)
#3frame#5143161 k54/53ch (registered as 1978 model)
#4frame#5144754 k54/50(?)
#5frame#5177862 k54/504
Any help to confirm build year will be very much appreciated.
thanks in advance,
Derek

I did add the frame numbers but they dropped off:
5125792-k54-505
5141114-k54-504
5143161-k54-53CH
5144754-k54-50?
5177862-k54-504