Transwede, what time of day was this?
The only regularly scheduled DC-8-70 is the ATI one that comes in around 9am, but varies at times give or take an hour. It has a blue tail, although sometimes still in green and white Burlington colors.
I moved away from Orlando 2 months ago, so maybe UPS or DHL are flying them there that I am not aware of now.
On the Orlando Airport website under new service it claims that Virgin will be flying 8 times per week between
MCO and
MAN so that obviously means that at least one day a week you will see two flights from
MAN.