The DHCP on your server can only give out addresses to clients that are on the same subnet as one if it's NIC cards.
I would suggest moving the static IP to your gateway router's WAN port (don't use this router in bridge mode), setup NAT & forward traffic headed to your public IP to the internal IP (10.10.1.x) of your server (you will need to change your server IP to be on the internal subnet (10.10.1.x). Your server's gateway should point to the internal IP (LAN) on your gateway router (also on the 10.10.1.x subnet).
You could also add another NIC card that can be assigned to your internal (10.10.1.x) subnet and connect the workstations through that port. The NIC with the public IP would need to be connected directly to you gateway router and you would need to setup a default route within your server to route your client's internet traffic through it to the gateway router.
I think the first option is the better of the two, of course depending on your ultimate goal.
Does this make sense?