A lot of people think that there are no aftermarket options for a Marlin model 60. That is not the case.
While it doesn't have the aftermarket support of the Ruger 10/22 (few guns ever have), options do exist.
For a long time the ATI Fiberforce stock was about the only aftermarket stock available, now you have more choices see the ATI stock here
Here is a unique rear peep sight from Skinner Sights that will fit on the scope groove of your Marlin.
At one time Muzzelite made a bullpup stock for the model 60, while it is discontinued, you may be able to find an NOS or used one.
Diversified Innovative Products (DIP) has several upgrades for the model 60.
The have a drop in aluminum trigger, it is adjustable to remove the pre-travel.
They also have aluminum trigger guards in black, silver or gold, you can also buy them in a kit with the trigger.
DIP also has a variety of bolt charging handles for early and late model 60s, 3 styles and 2 colors.
DIP also makes this 3/8" Picatinney rail that fits over the factory cast in rail. See them here
Another 11mm to 20mm Picatinney conversion rail is from Combat Hunting.com.
Badger makes these great bullpup stocks for the Marlin semi-autos (model 60, 70 and 795). They come in several colors, although their website only shows the brown marble color now.
They also make the scope mount, which allows the use of standard eye relief scopes, although their website doesn't show them currently.
Williams makes their Fire Sights as a direct replacement for the factory sights on your model 60, you can get them from Brownells
M*CARBO has a spring kit for your model 60, replacing the worn springs and reducing your trigger pull down to 3.75 lbs, you can buy them here
Hunting Tactical makes these replacement tactical stocks,
For awhile Elfmann Tactical offered this bull pup kit, they discontinued it, but promised in 2016 that it would return. It is not currently listed on their website
NECG makes these steel peep sights, they fit the 3/8" scope groove and come with two apertures, Brownells has them
This guy named Jason built a bunch of charging handles and was selling them on ebay, not sure if he has any more, here is his blog page
Uncle Mikes sells a kit you need to sling your Model 60, see them here
Here is a unique slip on sling mount for the Model 60, an ebay seller had them available,
Boyds offers several laminated stocks including their popular SS Evolution Stock (in multiple color choices)
Tech Sights also offers a rear peep sight that mounts to the cast in rail, they come with a front sight reminiscent of the M1 rifle, you can see them here
An ebay seller is selling these brass replacement magazine follower for the model 60 and variants, see it here
U.S. Gun Stocks has these fine English Walnut stocks for the model 60
If your bolt buffer has bit the dust, Gun Parts Corp can set you up with a new one
You can get new trigger guard screws from this ebay seller, they come with the hex key
Bayou Gun Slings makes a leather sling just for the model 60, see them here
Gun Parts Corp has these factory checkered stocks available for a reasonable price, they have a cutout for a medallion, not sure where you would find the correct medallion (in this case it was a Ducks Unlimited one), maybe install one of your own? They are listed as walnut, but are actually just stained hardwood. See them here
One way to spend more time shooting when out at the range or your favorite plinking spot is to buy some of these speed loaders from Spee-D-Loader.net and load them with cartridges before heading out. See more here
Another option for a rear sight is this Bullseye model from Marbles, Midway USA has them for you
There are plenty of companies than make a scope mount to fit the 11mm rail cast into the top of the Model 60's receiver. Here is one from Umerex/RWS, get it on Amazon
If you want to step up to a better quality unit, check out this billet aluminum one from DNZ Products, they are 67% lighter than comparable units and are precision made, right here in America! Ochocos has them for you
At one time RamLine made these tactical folding stocks for the model 60, but they are discontinued now.
Ragged Hole has these slip on extensions for your model 60's charging handle, see more here
If you would like to add a muzzle break or other accessory that uses 1/2-28 threads, Infinite Products has a slip on adapter for you
If your springs are worn out or you just want to have the best internals parts available, J&P Gun Springs has a set made from Chrome Silicone, see them here