Okay - deeeeeep breath - here we go!
150 is considerably under the auction average price. I would have bought it for that sum.
This example is an M91 moschetto. The M91/38s were made after 1938. Generally speaking, the M9/38s have fixed sights... except for FNA...
Before 1938, all cav carbines had adjustable rear sights - after 1938 only FNA have them. Why FNA? My best guess is that they had a quantity of the adjustable sights leftover and didn't want to waste them. You see that a lot with Italian rifles - they wasted very little.
The stock cartouche is most likely the standard Gardone stamp. A clear, sharp stock cartouche is a very good indication of a vet bring back. Unless said vet sanded it himself. For some reason, stock cartouches were obliterated on export rifles.
Most Carcanos only have numbered stocks and barrels. Early long rifles had numbered bolts as did Roma M91 long rifles for their entire production. An all matching long rifle stock, barrel and bolt is worth a premium. No force matching, but parts were freely swapped at arsenals during refurb with little attempt to return parts to the same gun.
Then! Civilian Beretta and FNA TS have about everything numbered to the gun. No letter prefix to the serial number = a gun from the civilian range. Not common at all.
I really can't comment on the Serb ammo since I shoot only cast bullet reloads. I've not heard much negative about it, though.
Prices on the Finn short rifles seem to be rising... not that people are paying that much. They really don't bring any kind of premium - in fact, the non-Finn M38s are worth at least 50% more. But the Finn riflles are most often in very good condition probably because they saw little use. A Finn author has reported Finn trooops would throw their "Terni" away as soon as they could pry a Mosin-Nagant from someone's cold, dead fingers.
When examining a non-Finn M38, always look on the bottom of the stock just ahead of the rear sling swivel. There just MIGHT be a German armorer's stamp. Many of these were siezed from Italian arsenals after the king surrendered in 1943. An armorer gave each a cursory inspection and made the mark to show the rifle was fit for service.
No worries with questions! I can rattle on all day about this stuff!
SW