I have a Kenmore very similar to the first one - that thing is built like a TANK. Mine takes standard class 15 bobbins. I really like it, good solid strong machine and I even like the looks of it. Mine takes cams, this one looks like it has a stitch selector so might be younger than mine.
The brown Kenmore looks older but I am not familiar with it. Kind of looks like same finish on a Kenmore I have that was made by White in the late 40's but very different body style from what I can see.