You can easily enough figure the change in POI :
(ETA: Apologies for the "........"! Text wouldn't line up otherwise.)
Sight height change = POI change
.....Sight radius.......... Target distance
So,
POI change = (Sight height change) X (Target distance)
............................................Sight radius
Just keep your units the same for each variable! Since you are working with inches, stick with that, i.e., a 0.005" change in the rear sight will go with a 3600" target distance (assuming 100 yards) and whatever the sight radius is to the back edges of the front and rear sights. Call it 20", subject to verification.
Zo,
POI change= (.005" X 3600")/20" = 0.900"
Looks like slightly under 1MOA for each 0.005" change. (Noting that 1 MOA is very slightly more than 1" at 100 yards! 1.047", I think)