For The Love Of Port

I picked this up as part of a mixed lot at auction. I've not found any information on this vintage or anything else about this Port for that matter. Anyone else ever seen it or know anything about it?

It has the old style Selo, so bottled quite a long time ago. The fill is well into the neck and appears to have been well stored.

I assume it's a Colheita. There is some sediment floating around in it that could be seen.