My Rear is Dripping

[Anthony Woodruff <tonymmedia@yahoo.com>]

Under the right-rear of my 67 MGB Roadster is a pool
of what appears to be black oil.

There's a chance that my son was goofing around a
spilled it (wishful thinking), but more likely my rear
shock is leaking this gastly fluid.

Question:  How can I test or fix?  Should I top-off
and forget about it until later?

TIA,

Tony Woodruff
'67 MGB.