Some solutions

In response to the questions asked:

1969 BC 10


1969 BC 23


1969 BC 10 and BC 23 Video

1969 BC 23 continued and 1973 AB 31 and 1973 AB 37 Video

1973 AB 31


1973 AB 37


1985 BC 28


Actually, the answer is E to 28 above. I did the right work and had the right answer, but wrote D. Sorry.

1985 BC 33


1985 BC 28 and 1985 BC 33 Video