I have no idea what publication these Praktica pages came from but they are very informative. I have used the original scanned pictures but retyped the text for clarity.

Praktica - The early models:

Praktiflex:

The original Praktiflex is easily distinguishable by it's smaller lens mount to which none of the current lenses can be fitted.

1. Transport, shutter tensioning and mirror return knob
2. Rewind button
3. Shutter speed knob (no slow speeds)
4. Shutter release
5. Focusing and viewing hood
6. Rewind knob
7. Back latch

1952 Praktica:

The 1952 Praktica is the true forerunner of the modern range. It took over the 42mm lens mounting of the old Pentacon or Contax S and introduced the delay mechanism for slow speeds that all Prakticas used until 1965.

1. Transport, shutter tensioning and mirror returning knob
2. Rewind button
3. Shutter speed setting
4. Slow speed control
5. Shutter release
6. Focusing and viewing hood
7. Lens
8. Rewind knob
9. Back latch

Praktica FX:

All models before the Praktica IV were the so called waist level types. The main features of the Praktica FX2 were as follows:

1. Transport and shutter tensioning knob, which also returned the mirror to the taking position
2. Rewind button
3. Shutter speed setting
4. Slow speed control
5. Shutter release
6. Focusing hood. re-designed to take an attachable penta-prism
7. Flash contacts
8. Rewind knob
9. Back latch