Here's a video I just took.
I believe the model is a RGPS. Gas, updraft. I need to find the papers on it...
As for the registers.... there are 5 downstairs and 4 upstairs. The are all approximately
(did not measure).... 4" x 10" each. One downstairs is kept closed since it's only 4 feet from the T-Stat. The house is pretty small Sq Ft about 1100 or so.
I just remembered..... Here are some pics of the old furnace when we bought the house 17 years ago. I cleaned up a lot of that mess since. You're gonna love how the previous owner had the AC condensation drain set up!!
To give a better idea of the size house, here's pics of it.