Many folks hate to complain, but if this is an ongoing manufacturer's issue that perhaps has already been known or resolved by Pedersoli, why not complain to either Pedersoli or their US agent, the Italian Firearms Group in Texas and begin by asking for a new set of sights after describing the problem.
You can also provide the serial number and the original receipt of where it was purchased if you care to bolster your complaint.
It was posted in a Colt sight thread just today that a front sight needs to be raised about 1/4" to raise the point of impact of a 10.5" barrel 10 inches at 25 yards.
I believe that may be based on a known formula.
In other words, you had a choice to either raise the front sight or to lower the rear sight, or a combination of both.
If the rear sight is unacceptably low now, then that is not only a basis to complain, but can also serve as more reason to ask for a new sight set so that you can find a way to acquire and replace the rear back to original configuration.
A front sight can be built up by adding solder to the blade or by soldering a new blade to the base.
A sight base that's too wide can also be made narrower to fit instead of changing the dovetail.
And in the process, try to duplicate the contour of the original front sight if you want to.
It's usually preferable to alter the least expensive part rather than the most expensive part.
In this case the front sight instead of the barrel and it's dovetail.
Unfortunately, you already altered the rear sight a lot, so perhaps you really would prefer that Pedersoli provide you with a new one.
But that's up to you to decide.
Also, Pedersoli has an authorized repair facility at Lee Shavers gunsmithing according to the Pedersoli website.
Maybe they can help you out if you contact them with complaints about a new gun.
If necessary, let Pedersoli know that you're a loyal customer and that you expect them to help you out or risk losing your future business.
People have written letters [or personal emails] to the president of a company for far less reasons and have received their personal attention.
You can also try Track of the Wolf or other vendors to see if they have any sights with bases that will fit your dovetails and will meet your needs.
VTI Gun Parts is probably the largest Pedersoli parts distributor in the USA.
I wish you success obtaining satisfactory results.
The formula for front sight adjustment or replacement is:
Record:
error on target in inches
distance to target in inches
sight radius in inches.
divide error on target by distance to target,
multiply by sight radius.
The sight radius is the distance between the front and rear sight expressed in inches.
If the rear sight is adjustable, adjust it to the middle of its adjustment limits to allow a range of adjustment up or down after replacing or modifying the front sight.
For example, if the sight radius on a pistol is 10 inches:
error on target= 12" low.
distance to target is 900".
sight radius is 10".
12" divided by 900" = 0.01333 x 10" = 0.133".
The front sight has to be lowered by 0.133 inches or a bit more than 1/8 of an inch (.125).