ACESES5
I'v had the same probluem go to a good hobby shop get you a bottle of Microscale Superflim
I think you mean Microscale Liquid Decal Film.
If you apply this to the whole sheet, you will need to trim each decal very closely before applying, as it effectively adds a layer of carrier film (albeit on top of the existing decal)
With care, you can apply to each individual decal. Apply as thinly as possible to minimise any additional thickness to the decals. Any apparent brush marks will self-level as it dries.
I have used this stuff successfully with 20+ year old decals which otherwise broke up with the curling of the backing paper when dipped in water.