On Sat, 23 Nov 2013 16:41:36 -0600, The Daring Dufas wrote:

It actually looks like someone has replaced that electrolytic before.
Oh yea, looking at your other pictures, it now looks like the board was
manufactured in 1998. ^_^

There were unused leads for two batteries, so, I suspect there were
two batteries in series initially. The battery in there now doesn't
look all that old. The equipment was made in the 90s as you surmised.