Johnson L1600 bilge pump question

[Just me again]

I have a Johnson L1600 (I think) but the label is unreadable. This is not a newer model with a screw on top, it's a 2004 vintage. If it helps, the cap is red and the discharge is straight and not angled up. The basic question, are the bases interchangeable, if not are there some in this size range that are?
Going a step further, which bilge pumps have an internal float switch. This has an Electro Magnetic float switch but I have only a 8" access hole in front of the motor to get this done.
​Thanks