vendor finance available

I've also posted this under "Wrap Info", but "Finance" might be a better heading.

I am contemplating the sale of 3 properties:

1. Dual Occupancy approved, ie stamped plans and permit for a 3 bedroom, 2 bath, double garage,
Safety beach, 50 m to beach, almost next to Marina. Front house solid and easily renovated cosmetically.
Around $520,000.

2. Cabin in a seaside caravan park , almost new fully furnished.
$115,000, suit 1st home owner/retiree with limited funds.

3. 4 bedroom, 2 bathroom, fully renovated, including furniture, Merrijig near Mt Bulla, around $400,000.

In this slow market, I am willing/able to provide some vendor finance at 5.5% interest only for 2 years on a deposit of approx 1/3, and being the the first mortgage holder.

Would this improve saleability?
or What is the best approach?
Where are these properties best advertised?
I don't need to do a "wrap", as they are not financed.

Thanks, Regina