50-160 or so
Not worth more than 50 USD
Not worth more than 50 USD if in NIB condition.
If the revolver is an RG or Rohm, it is worth about $25-50. These were low cost, low quality firearms, and frequenly had frames made of metals other than steel.
The Dickson Commander appears to be the same basic gun as the RG model 40, built by Rohm in Germany. Probably worth about $100-$120 in VG condition.
It's your control of your trigger finger. There is no safety device on a Rohm revolver.
While the value of any firearm depends on its condition, the RG revolvers were very inexpensive firearms when new, and are typically worth $50-75 US.
25-65 USD
25-65 USD
10-100
$75-$100. The Rohm/ RG handguns were of low quality, and are not well regarded in general.
You let a gunsmith do it.