only 6? That's quite impressive!
Yep, I'll lay money on them being gonners. problem is the steering arm is one of the few bits of that engine made of steel (as opposed to alloy or stainless) so it's the first to start rusting & takes the other bits that have to be made of steel to survive the thrashing (the bolts) with it. There is also a chance the AV mount you are almost pointing at in the last pic may have (literally) come unstuck.
That's the bad news. The good news is those legs are common up to about 90 HP, and loads of Mariners use them too, so in a worst case scenario, finding a replacement shouldn't be too difficult. I was halfway to the PT conversion myself when I discoverd the earth strap to the powerhead had broken & it had turned to shortbread. DA Marine in Dundee has (had?) a very solid leg in his bits box, just don't touch the powerhead with a barge pole...... (serial number available if needed!
If it's any help I have a reasonable nick clamp / swivel assy off a 75 (it came free with the PT I bought!) if you are really stuck. Have a trawl in the "bits 'n'pieces" section for photos - Price negotiable as it's been taking up space for a while now!