A great all rounder the Swanson 27. Inventory list here of one - assume sold - which should answer most of your questions. Trust the data is valid but some may not be - the 3500kg displacement seems a tad high but it could be that.
sundancemarine.com.au/wp-content/uploads/2016/02/Schedule-1-Indigo-Swanson-27.pdfHow does the one you are looking at compare to this?
yachthub.com/list/yachts-for-sale/used/sail-monohulls/swanson-27/270483On line links indicate that one sailed out of SASC back in the day and had a fractional rig - it did very well as they all did when sailed properly.
Another link suggests the moulds went to Melbourne and the bubble cabin was changed to a more "cruising cabin" - but I have never seen one with anything but the bubble cabin. Are the plywood decks on the one you are looking at glassed over or varnished or nonskid painted or what? Are any deck areas soft and spongy or just poorly painted? Inside underneath the deck - the deckhead - is there any dry rot evident and are the timber support beams ok? Sounds like this boat is waiting for the right person to snap it up, fix it up with a bit of labour and suitable materials without over capitalising, and enjoy it. Still serviceable Etchells sails (cut down main luff) should fit ok and then just need a 130% genoa for the light breezes.