In 2003 I found a Sako M39 on a gun show table and dickered it down to $90.
I paid $35 and had the bolt handle TIG welded.
I got a quantity of gen 1 TAPCO AR15 risers for $9 each by dickering down Cheaper than Dirt on the phone.
I milled out an AR15 riser to fit the hex receiver.
I did not do a very good job. [This last week I finally figured out how to mill hex shapes in scope mounts for an 1892 Winchester].
But I put epoxy between the hex receiver and my bad milling, and the M39 shoots.