Duke PT brakes question

[HHTELE]

Due to the ridiculous price at Corbetts, I have 3 pair of Duke PTs on the way.
PT 16 x2, PT 13 x 1.
My question is about the brakes.
1- any reason 13'3 and 16's would have different brakes?
2- do they retract in at all? 125 brake on a 105.

[tenB]

Same brakes on 12 and 16.

Brakes retract, but if you use 125 on a 105 ski, you will catch the brake arms when you tour, far from ideal. the 100mm brakes easily fit 105 without bending or trimming plastic on brake arms