Without more specifics, 10-1000 USD
Depending on EXACTLY what you have and its condition, the range could be from a few hundred to multiple thousands of USD.
If it is a U.S. patent, you can go to the USPTO website for patent searches and enter the number in "patent number search".
Patent pending is a warning that a patent application has been filed. It is completely worthless until and unless a patent is actually issued for that invention. Patent number notice means a patent with that number was issued for the invention that is implemented in the product labeled with that number.
the patent number is 5209584
There is no specific patent number for the mailbox.
A patent number is the code that helps identify an invention.
The value of any firearm is based on the exact make, model and condition. Your Walther self loading (selbstlade) pistol has some degree of collector's value, which will be driven by condition. You will need a hands-on appraisal. Take your pistol to a local gun shop or gun show. There were at least 4 different versions made, and values are typically several hundred dollars- again, based on model and condition.
The US patent number is US 7198789 B2.
You communicate with the Patent Office.
There is no US patent 555408021. There is also no US patent 55408021.
The phone number of the Holland Patent Free Library is: 315-865-5034.
The Frisbee patent was issued on September 30, 1958 as Design Patent number D183,626.