Quote:
"could someone please explain reasons for a reperf"
There are many. Maybe the most obvious is to deceive (to add fake perfs to a more common stamp to create a more valuable-appearing stamp, e.g. produce a fake Scott 388 coil or fake Scott 519 from imperforate stock). Another common reason is to create a more aesthetically desirable (and therefore a more valuable, if the alteration is not disclosed) example of a genuine stamp, e.g. adding perfs to straight-edged stamp, or removing damaged perfs and adding fake perfs that look perfect. I'm sure others can add to this list...