The are two clip type master links. One is like you would see on a chain found commonly on motorcycles or various machinery. This type has one long split clip that fits over BOTH pins. The second type has two E shaped clips that fit individually over each pin.

In early MB's, the E type clips were used. With later chains, the permanent link was used. Although the two E clips are probably adequate, I prefer the peened or pressed clip.

There is nothing wrong with buying the tool, it's just that it's not necessary for those who are competent with the few steps needed to peen it properly with hammer and dolly.

Good luck,