Is this the correct magneto for my phone?

[xtal_01]

Hey Guys!

As you may have seen, I am trying to find the "correct" magneto for my 1929 105A Leach phone.

     http://www.classicrotaryphones.com/forum/index.php?topic=22064.0

According to what I read 105 means it should have a 5 bar magneto (103 a three bar and 104 a 4 bar).

I have a 3 bar in in it now.

One of the posts said to try "the old phone company".

I did and they said they have a Leich magneto.

It is in what I would call a "ringer box"? 

It looks correct.  Can I assume (I hate assuming anything, this is why I ask) that this magneto is the same that would have been in my phone?

I have attached a few pictures.

Thanks !!!!!

Mike