Python 2, 156 bytes
r=('AaBbCc.BbCcDd.EeFfGg.HhIiJj.KkLlMm.NnOoPp.QqRrSs.TtUuVv. WwXx.%8cy.%10c.%10c'%(89,90,'z')).split('.')
for k in r+r[-2::-1]:s='%-10s'%k;print s+s[::-1]
Maybe the formula 512/(i**4+47)-1
is of interest to future golfers: it maps the integers around 0 to $$\cdots,-1,-1,0,3,7,9,\fbox{9},9,7,3,0,-1,-1,\cdots$$
which encodes how many spaces to prepend to each line ((-1)*' '
being equal to 0*' '
).