Can't be answered without a detailed description of ALL markings, condition, history, accessories, etc..
Depends on who did it, how long ago it was done, quality of the work, etc..
270 mauser modelo argentino deutsche waffen-und munitionsfabriken a2608 berlin B
Yes.
No, you cannot shoot .270 Winchester ammunition in an 8mm Mauser firearm. The .270 Winchester has a different case size and bullet diameter compared to the 8mm Mauser, which is designed for 8x57mm Mauser cartridges. Attempting to fire the wrong caliber can be dangerous and could damage the firearm or cause injury. Always use the correct ammunition specified for your firearm.
100-1000 USD or more depending on specifics.
.270 has been around since 1925. You will have to contact FN to check on the sn.
100-1000 depending on specifics
10-350 USD, no.
In mm 635*285*270
I-V and custom
these nuts
My F.N. Mauser in .30-06 s/n 4570 was made in the mid 1950's. I have been unable to learn any more regarding the F.N. mausers. It is a true a classic, hope this helps