Thanks for the advice so far fellas, seems like it's not a practical conversion whatsoever.
A few notes on my particular example, it is an ex-German rifle whose receiver appears to have been heavily butchered by Bubba. It currently has two off-axis holes in the receiver by the chamber, plus one at the rear. I can also make out several TIG welds that look to cover additional holes, one of which obscures the manufacturer code which is either DOT or DOU 45. Several Israeli markings adorn it.
Most interesting about this particular specimen though is its two digit serial number. Matching parts seem to include the bolt and barrel though I'm not sure how the latter is possible since it's a 7.62mm, unless the Israelis renumbered it perhaps? The stock itself is in very good shape with almost an orange tinge to it and appropriately marked 7.62 on the underside. The cupped butt is the late-war style with the hole through the side.
Overall an interesting piece. I've abandoned the cleaning rod idea and think I'll satisfy my urge to "origify" it again with a repro front hood.