FW, Ruger subs out many aparts of their firearms and they then become..basically an assembly crew....AND..it is the RUGER policy not to sell parts to any parts of the market place...You can be a practicing famous gunsmithing operation and still not get parts..Most Ruger parts are factory installation only and they won't even get into a discussion. They simply say that this outdated version of the Model X is no longer supported by the Factory. It has been this way since the very first Ruger Standard Pistol was sold. There are a few operations that get parts from Ruger..but they are all Authorized factory repair stations. You may be able to access a list of these from the Ruger webpage and one of them may have some "new: old shelf stock
Other than that, the best source of Ruger parts...restricted parts will be someone parting out a gun..Make sure the parts are from your same block series.......I take note that you say pinned to the reciever...but I glanced at several versions of the rifle and I only see a Trigger Guard assembly and no independent listing for the part shown........If your gun was modified in the aftermarket, then your part may be unique. You may need to find a triggrtguard assembly that will service your gun...Monitor E-Bay or gunbroker.com for a parted out gun. You might want to consult these:
He will supply and install restrict parts if he has them..Google him
You can also check with these dealers
You may have better luck in Canada..try
The Ruger 77/22 rifle is a versatile hunting rifle that can be used in a variety of outdoor scenarios. It features a 22-caliber rimfire round, which is small enough to be shot out of most smaller-caliber guns. This makes it a great option for hunting small game in places where larger-caliber rifles may not be able to fit. In addition, the short barrel allows it to be used for target shooting and plinking.
Word at Subway surfers - Chesterbob