I've fired many Marlin, model 60's and never had any problems with any of them concerning accuracy, jamming or longevity. I only had jamming issues if the rifle had loose screws (which you should check for on a routine basis with any rifle), was super dirty and/or needed oil, or if the ammo was dinged-up. I've found them to be more reliable and more durable than any other 22 rifle I've used.
I also own a Marlin, model 99 M1, semi-automatic rim-fire and I've had the same consistent results of excellence in its performance - be sure to use only 22 LR ammunition. However, I will admit all of the model 60's I've used and the model 99 M1 were all over 30 years old. The stocks on mine are all hardwood and actual walnut, not just walnut finished. Just like every other manufactured product that has been around for many years, better and more solid materials were used because the older ones were built to last, and also they were built with craftsmanship and integrity.