Try e-gunparts.com
At a good gunsmith's shop. Maybe Numrich's Gun Parts (search gunpartscorp) For the complete trigger guard assembly, including trigger, safety, springs, pins etc., you can get it from Numrich, Midway USA, Brownells or direct from Marlin. If it's just the trigger or other individual trigger guard parts you need, you'll have to get those from Numrich for a different model Marlin.
gunpartscorp website.
The bolt is removed from a Marlin model 81 by first opening the bolt completely, then while holding the trigger back all the way, continue to pull the bolt the rest of the way back. Sometimes it is necessary to hold the trigger back while re-inserting the bolt.
You need to find a copy of Brophy's book on Marlin History
marlin mod 81 dl 22
No, a Marlin 881 stock cannot fit in a model 81. The stock would fit an 881, not an 81.
Marlin 81
this is a bolt action rifle
To adjust the trigger on a Marlin XS7 .308, first ensure the rifle is unloaded and safe. Remove the trigger guard to access the trigger assembly, then locate the adjustment screw, typically found at the front of the trigger. Turn the screw clockwise to increase pull weight or counterclockwise to decrease it, making small adjustments and testing the trigger pull until you achieve your desired weight. Always remember to reassemble the rifle and perform a function check after adjustments.
Your Model 81 was halted in the year 2003.I would surmise that Marlin had a new model in the works at the time of the model 81 demise.
The trigger guard is available from Numrich Gun Parts. There are two different types of trigger guards for the Savage 6d. The plastic guard that has a inletted area for the trigger guard in the stock and the simple bent metal trigger guard that just screws into the stock wood. Plastic trigger guard is product # 103530U $24.10 Metal guard is product # 10543OAL $11.50
Marlin 81