E-gunparts.com, gun shows, gun shops, want ads.
There are numerous online sources and parts dealers at gun shows. The largest are Numrich Gun Parts and Gunbroker, but if you web search for that model you should find several different sources.
One can get spare parts for a Nikko shotgun at some local gun retailers or through gun manufacturers. Gun parts can also be found through gun classifieds and gun auctions.
The Unique has been out of production for some time. I did check my usual on-line parts sources with no luck. Your best bet will be to check gun shops, on-line gun auction sites, and gun shows. Sorry
Numrich Gun Parts is the default. You can often find cheaper parts at other vendors. Search online with the model and "parts" and you should find several sources.
There are several large parts suppliers online. You'll need manufacturer, model and sometimes date or serial number. Numrich Gun Parts Corporation has exploded diagrams you can use for reference. A search for "gun parts" and "Charles Daly" should find you several sources.
Try these sources: Numrich gunpartscorp.com Jack First jackfirstgun.com Bob's Gun Shop gun-parts.com
Midway usa sells tons of model 700 parts. They are one of the biggest sources of general gun parts both online, and catalog sales.
Some parts of a glue gun include the nozzle, trigger, heating element, and stand.
Actually, that is Western Field. That was a store name used by the Montgomery Ward department store for guns sold by them (but made by others). In the case of your gun, it is a Noble Model 70. There are SOME parts available on line at gunpartscorp.com. A gunsmith will have access to other sources for SOME parts. I specify SOME because that gun has been out of production for about 50 years. Good luck.
I seem some parts for your gun on e-bay
Gun Parts Corporation is the main supplier of Numrich gun parts. On eBay, one can find Numrich gun parts. On Amazon, one can find a few Numrich gun parts.
You can purchase some AR15 parts from places such as OpticsPlanet, m4broker, Tactical Intent, Cabela's, and you should also check some local gun shops and gun shows for some accessories.