AusBonsai

Hi all, I got this little tree back in October last year. The person I got it from had the trunk coiled up like a spring. I wasn't the hugest fan so I carefully uncoiled it. There were some cracks from the coiling so there are some thicker lumps where they healed on the trunk but hopefully this doesn't cause too much trouble with reverse taper.
Today I decided to give it a haircut, it had grown quite the afro. I foolishly got straight in without any photos.
I added some wiring and which I'll leave on for a week or two, keeping an eye on how it bites in.
I'm still very new to bonsai, I started in October last year with this tree.
The main concern I have with the tree is the bare bottom part of the trunk and the thicker parts giving some reverse taper.
I'm wondering if I should/can air layer the top off but I'm not sure how that will go with such a thin trunk still.
Anyway, I'm learning on the way and I'm happy for any feedback.

Most Mels layer well so that is a possibility.
This is not very big. Rather than an air layer I think it would be easier to ground layer this one.
Split a pot and cut the bottom out to get a plastic cylinder. Put it around the trunk so it fits inside the top of the present pot. you'll probably need to put tape or wire around or staple the join so it does not open up when you fill it. Then fill the new pot with good mix and wait for roots.
It is pretty thin. Ringbarking might weaken the stem too much so I'd try tourniquet method with this one. Tie wire tight around the trunk where you want roots. As the trunk thickens it will make new roots just above the wire. It should grow roots without hormone with this method but if you want you can also paint some onto the bark at the point you want the new roots, just above the wire.

After all that advice I think it looks good as it is. Still very young but nice lines to the trunk and branches. I'm not sure that shortening it will improve it at this stage. Just need to keep pruning the top shoots to make it ramify.
Leaves look like M. hypericifolia which I've found does not shoot on bare wood very well. shoots will just get longer and longer without pruning regularly.

Thanks for the info, Neil is it?
I'm more inclined to leave it as it is at the moment too. If back budding becomes a problem, maybe I'll try a layer next year. That lower branch is the only bud I got all year, so hopefully this prune gives me some more to work with.
Also thanks for a possible ID. Hopefully I'll get some flowers one day!