There are presets in the MB Suite may emulate what you’re looking for, mix it with some edge blur/diffusion and maybe some over-grained chromatic aberration… also some carefully applied gradient blurs based on perspective gradients….
Don’t forget too, the beauty of consumer/low end polaroids (which is why I have 5 of them) is that they never develop the same way twice — and they are spontaneous. Take two pictures of the same composition at the same time, at the same place, and they won’t develop the same. Perhaps you want to take this into consideration when creating your preset.