Identification
Easy. The Type A razors are the only repeating razors with a round handle.
Stamps on the side of the stem
Some or all A Type razors have a number stamped on the side of the stem connecting the head to the body. Here are some examples:

Model A - ★27

Model A - ★37
Image: Norcalnewb@TSD

Model A - 37
Image: jmudrick@TSD

Model A - 47
Image: Hodge@TSD

Model A - 106
Image: GDCarrington@TSD
Examples
Type A with grooved, smooth handle
Images: jmudrick@TSD

Back view

Front view

Head front

Head back

Left side

Right side

Bottom view

Bottom cap

Razor and cap

Bottom cap removed

Razor with cap