The static IP's give the machines that have them, a public presence on the WAN. They can be contacted directly, assuming there isn't something blocking the pipe. With static your don't need to mess around with nat or port forwarding, vpn routers, or anything. You can load ssh or vpn software directly onto the static addressed computers and let them contact the remote vpn device directly.

PS You might want to check your subnet masks carefully. They are what determine if a packet stays on the LAN or is passed to the WAN. Given the list of static addresses earlier the mask should have been 255.255.255.216 216 is 39 after it was converted to binary, had all the digits inverted and then converted back to decimal.

Hope someone else will correct this if wrong.