Vim (no external tools), 106 bytes

Newlines for clarity:

:h<_↵↵↵YZZPllabc♥
:s/./\u&&/g↵
qa6li↵♥q7@a3i ♥fY
i↵    →→↵  →↵→ð♥
ʌHA ♥9l
qbmaʌ99jY$P`ah@bq@b
y11G:g//m0↵P

Here ↵ is Return, → is Right, ♥ is Escape, ʌ is CTRL-V, and ð is Delete.