My mother-in-law gave me a quilt top made in the 1960's or before and I plan to quilt it. Should I wash the top before quilting? Further, should I even wash it after quilting? I'm afraid I'll ruin it but I want it to be a useable quilt when I'm done.

I would never wash a quilt top until it is quilted and the binding is on.
The fabrics will ravel, and you could end up with a mess :D:D:D

Unless it smells bad, I would not wash it before quilting. Wash the finished quilt in Synthrapol with some color catchers just in case something bleeds.

You never want to wash a pieced quilt top unless you first baste it well to a foundation piece. Otherwise you will likely get a distorted, frayed mess.

Amma -- What if the fabrics shrink and make it even "wonkier"?

I agree with amma, wait until after you quilt and bind it...then hand wash or gentle, gentle cycle. Beautiful Quilt!

I had a tiny bit of an old quilt topo that I got in a yard sale. To make a side table topper I put some real thin muslin on the back and then zig zagged, almost satin stitched in the ditch all over the sewing lines. Had to add binding but still around in my daughter's house. It was "her" colors!! She has to wash it often because of allergies.

Love that pattern, never saw the blocks made that way.

I've been in eco mode, so for over three years now, I've only ever washed in cold water and line dried. I think if you quilt it (beautiful top, by the way!), then washed in cold and line dried, you would not get shrinkage problems.

If it is closely quilted, the batting will control the shrinkage (not the fabrics). In other words, close quilting stabilizes the fabrics so they cannot shrink beyond the amount the batting shrinks.

I wouold not wash it before quiliting, I think you will be sorry, even if you are very careful. If it has a bad odor, then you might stick it in a plastic bag with an unwrapped bar of Safeguard soap for a few days and then air it before working on it. I don't trust spray fabric fresheners

That is a wonderful quilt top!

Wash after quilting. The raveling alone might destroy it.