Without commenting on your gunsmith's rates,realize cutting and crowning your Moisin < $100 dollar Moisin is the same investment of time and effort for the smith as it would be on a > $3000 dollar rifle,though admittedly the smith may take extra pains with the expensive rifle.
I use a lathe,can't loan it to you,and wouldn't.Loaning tools is a losing proposition.
Try a hacksaw.Then use a file and a square,carefully making it uniform all around.Then use a 1/2 in round ,hard mounted stone with a little oil in a cordless drill,very slow speed,light pressure,to make a slight crown recess.You dont need much.A ball will sit full contact in a hole.then use a 90 deg pointed hard mounted stone held in a pinvise,turned with your fingers,to just barely break the corner.
File a chamfer around the OD,blend it a bit.
Thats not what I do,but if you want a $15 dollar job for your $90 rifle,thats it.