Too thin spruce top?

[Henning]

Hello, I was given a small acoustic guitar that somebody, most likely have out of mistake, sat on. I took it apart, repaired the cracks, thinned the top, changed the bracing (converting it to X), reset the neck and put it together. I start to worry that I've thinned the top too much. Maybe I have, maybe I havn't. Now if the top has been thinned too much, can that be remedied, please?
Perhaps, adding a brace of spruce or perhaps even carbon fiber under the top in the right place, without killing the tone too much.
If I press on the top, beneath the bridge towards the end block, I can make it flex noticeable. No other guitar that I've tried that on behaves like that. It's a smaller guitar 580 mm scale length, about 3/4 of full size. Can I try this in any other way then setting the strings on the guitar and try tuning it, please?

Best regards

[Glen H]

String it up. You have nothing to lose. Maybe use an extra light set of strings first. Silk-n-steel maybe.