Thanks for the update. I'll get you super-specifics in the next couple of days, but here's what I know about the filter off the top of my head......

It's a Hayward. As for age, no idea. We bought the house in Feb. '06 and haven't changed anything out. The people who had the house before us had the pool built in the early 70's, but I know the filter isn't that old.

For the multi-port, it has 6 positions.... filter, backwash, rinse, closed, and 2 others. Not sure of the brand.

I probably won't be able to check the inside until the weekend.