I found The Mach 2 1/72 C-123 Provider model in a friends garage among the pile of models that he didn't want or would never get to. He sold it to me for 5.00 which is about what it is worth.
There are no pins to help with line up of parts, and the parts themselves just do not line up very well anyway, so pins wouldn't help at all, and many of the parts are not shaped correctly to each other.. also there is lots and lots of flash, and in order to line the parts up for gluing, you will find yourself doing a ton of sanding, and dry fitting and more sanding etc etc.
Now since this was an old model found in someones garage, I cannot speak as to what a brand new in the sealed box model would be like, but this one that I got had very little instruction, and and the directions that were there really really stunk. I basically had to build this model with very little help from the kit instructions.
Yes I have built it, and with the landing gear up as half the gear struts were missing, and after lots of sanding, cutting, scaping blah blah, it came out looking just OK. It is a cool looking airplane with a interesting history, but hopefully there is a better kit out by now (2017) if this is a model you want to add to your collection.