That is the T-900 system, restricted by Marlin. sales@countrygunsmith.net
Try Gunpartscorp.com also known as Numerich
"go to DIP and buy a target trigger for around $30" I take it from that statement you don't own the DIP trigger. I do, it's been on my 60 for over a year, it does not reduce trigger pull. It's a great rigger, I like the straight profile over the curved Marlin trigger and the adjustment for trigger pre-travel, but it doesn't reduce trigger pull. This has been confirmed by several DIP trigger owners and my Lymann digital trigger pull gauge. There is no simple fix for reducing trigger pull on a Marlin semi-auto. The action has to be taken apart and have parts replaced or modified to reduce pull weight. For anyone really interested in reducing pull on the Marlin 60, 795 or other variant of the Marlin semi-auto, you should log on to Rimfire Central forums and read the information provided in the stickies of the Marlin sub-forums.
You can get them from Marlin....
If your Mdl 42 is a bolt action 22 rifle, it is a Marlin Mdl 80. There were 5 different trigger guards used at different times. Go to the wbsite for gunpartscorp, select M, then Marlin-Glenfield. Model 80, scroll down to part 78. Some of them are in stock.
You cannot replace the trigger buy itself but you can buy a new trigger with new trigger frame like in the related links:
Which company?
No
midway usa.com
There is no best place to buy a gun sear since each state sells different guns and ammunition. The best options might be a local gun store, a sporting goods store, or a pawn shop.
On some guns you can change out the trigger springs, others you may have to buy a new trigger or trigger assembly.
you can buy them from lowes :) only $1.95
buffaloarms.com. They are expensive.