My favorite old hand sander is nearing the end of it's long life and nothing I've found to replace it is quite the same.  So - I fired up the Miraco and scanned it, did a little TinkerCAD touchup and here we have it.

Print in  the body and holders PETG, PLA+ or something else strong with lots of infill.  Print the pad in TPU (20ish% infill).  

Glue the pad bumpy-side down (towards the sandpaper) to the body.  I used Shoe Goo because it's flexible and what I had on hand.

Use machine screws of your choosing from the bottom up through the holder blocks (print 2), and use a wingnut to clamp 'em down.

Enjoy.