Tips on finishing basswood

[McCreed]

Is poly for the clear coat, which Colin said I could also Scandinavian oil for?

Yes, poly is used as the top coat. There are polymerising oils like Scandinavian Oil which you can also use. It's all personal preference, providing the top coat is compatible with what under it.

There is a wipe on at bunnings which is $39 for a litre, so the above plus turps only works out a little bit cheaper once you thin it, so now I'm not really sure what I'm looking at.

Yes. The Cabothane is what many here use (including myself) but 1 litre is way more than you would use on one guitar.
I buy the 250ml can, which cost $14 and it lasts me ages. For example: I generally only use it on necks, and I spray it with a gun, but the last neck I did, I used about 120 ml of poly/turps mixed at 60/40. It was approximately 12 sprayed coats. Wiping on will go on much much thinner and build-up will be slower.

Note: 60% of 120ml mixture equals 72ml of poly.

Another question. Is there anything that you can substitute for Tru Oil? I saw this post https://www.buildyourownguitar.com.a...l=1#post199734 and thought that the basswood came up quite nicely with the oil not being tinted.

Some people have had success with a 'home-brew Tru Oil", but I had no luck with it. YMMV.
Tru Oil has boiled linseed oil in it, thus giving it a slight amber tint naturally.

Poly can be very lightly tinted to the same degree or any colour for that matter. Untinted poly will also change the appearance of the wood, albeit less amber than Tru Oil. Poly tends to age less (called yellowing by some) than Tru Oil, but it will age.