I haven't worked much on the model 70's.  I can tell you that I was at a salvage yard in Wishek, ND a few years ago &amp; they had several 70's there.  You might be able to find a used one there.  I believe the place was called Martell's Inc.  I can tell you the owner can be &quot;tough&quot; to deal with but on the otherhand he was fair.  I bought a super 88 LP from him, I thought the price was high, but he threw in another motor on the deal.