Southerly, I'm not familiar with this boat, but if I knew where it was could perhaps have a look.
It's difficult to tell what's wrong with the mast step and mast base by those pics. It may pay to ask the seller what he thinks the problem is.
The bow however could be an expensive problem, as from what I understand there is some timber in the deck right at the point where the deck steps up about two inches and joins into the pointy bit under the forestay chain plate. It looks by the photo that there has been some seperation there, which could mean that the timber is now exposed and rotting. This would require either good timber and glassing skills, or a purse to have a shipwright repair it.
There is a decent amount of growth on the hull, which if it's been properly antifouled, may pose no problem, but if the antifoul has been breached it may be a more expensive clean up, and no survey will tell you the condition of the hull, unless they clean it, at your expense.
When in pristine condition, this boat may fetch $15k, as it's lined and has an enclosed head. So it's a matter of working out whether you spend $5 - $10k on a reasonable boat that is ready to sail, and in need of some routine upgrading, or $2k on a boat that may need $10k or more before you can hoist the main....
Check the other for sales, there were a couple of Mark 1s that may be a better option.
viewtopic.php?f=4&t=946 Mark I
http://www.boatpoint.com.au/boats-for-s ... R=12628100 a Mark III
http://boatpoint.com.au/boats-for-sale/ ... R=11393228 Mark III with a diesel
http://boatpoint.com.au/boats-for-sale/ ... R=12475985 in Dalrymple Yacht Club Tasmania
Lots of choices, depending on whether you want work, or play.....