I found a similar photo done (probably by someone more experienced), however I can't give credit due to the page it was pinned to was removed. This is my novice attempt.
It started with a 8x10 photo of Mr.-1yr-old framed (Picture was printed in color).
My hubby posed with that frame, which then was printed in color and placed in the exact same frame.
Then his father repeated, and then his father.
I am ordering this in 11x14 size (so that Mr.-1yr-old is not microscopic). I am crossing my fingers that it will turn out.
Will be looking for frames for the final prints and will be giving to grandpa and great grandpa as gifts.
If all goes well Miss.-3yr-old, myself, my mom and grandma will be the next to pose.