The M70 was put together with brads, so you would not be able to convert it. the M70 is worth way more that the war 9/32 dr rats, so why convert, sell it.
I was looking at buying one but the seller said it was 1/4. I just wanted to make sure that it was in fact a 9/32. The seller got back to me after I asked him to check the size and he said It was actually 9/32