Unless I'm missing something from your description – I believe, from your image that, this is the 1877, 20 Centesimi, orange, Victor Emmanuel II, Scott # 36 which IF in Unused condition, F-VF centering, without flaws would have a $3,500 USD value. However, it is commonly found in the cancelled condition shown, and currently is being offered for between $0.75 and $6.99 USD. If this is a different stamp please provide more information.
For the record: "Fco Bollo" is an abbreviation for "Franco Bollo", which translates to "Frank Stamp" (or postage stamp), since "franking" or "franks" are any and all authorized devices and/or any other form of markings affixed or applied to mails to qualify them to be postally processed.
not orange but the blue and is as you describe Viktor Emanuell II 20 centisimi 1877 nice preserved stamp, used, and if you're interested I have many more stamps we conspired to substitute for other things and I have a lot of Yugoslavian and other countries and leave the commentary function so that cujermo on my e-mail address ok fellow philatelist if you have coins or bank notes with me and numismatist