back cushions with no form - down

I have a sofa and love seat that I purchased about 9 years ago. A Rowe, Jenny model. The back pillows are down and have no shape as you can see in the photo (taken after fluffing it). We are looking to buy a new set, but in the meantime, I wonder if there is anything simple or not overly expensive to give the back cushions more vertical form. I would consider replacing the filling if there is a low price way. Maybe I should fill it with spray foam insulation (just kidding).

Hopefully the photo posts :)

Thanks

Attachment 10772
Here is the photo.

A good upholstery shop can repair those for you by adding Dacron poly-fill to them.

Hi Duane,
I took the cushions to a local upholsterer and he recommended the cheapest solution was similar to what you recommended. He will open both channels of each cushion and fill it with fill (turns out that it was not down as I had incorrectly remembered). After he fill them, he will attach two buttons across the middle of the cushions to pull them in so they don't look like giant pumpkins on the sofa.

Thanks again.

Alternatively, a soft foam bonded with dacron to help fill out the covers should help.