Please advise the master how to calculate the dimensions for this sheet metal unfolding, the plate thickness is 1.5mm without slotting!

L=124+205.87+17-3-3+0.525+0.525

The above is the inner size expansion method, and a friend below reported the outer size. Regardless of that method of unfolding is related to the plate and, V-groove, and many other things to achieve the unfolding of the dimensions.