The DPA guns are up to around serial #500.
The first 150 run were 4" standard civilian PC sales.
After that they were LE only.
The 5906 5" and 5903 5" are DPA serials also
S&W is still making batches on and off.
Guessing 450= 4" 5906
50= 5" 5906
10= 5" 5903

Prices on the 4" are $800 - $1000 depending on condition
The 5" guns are higher (I won't mention what I paid)

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PC semiauto collector