The acetone probably precipitated some of the substances from the buffer, and some of the mass may be residual solvent. If you resuspend your pellet in distilled water (assuming the protein is insoluble in water), centrifuge it, and dry down the pellet again, you should remove residual buffer components (which are soluble in water) and solvent (which is miscible with water).

Some of the mass increase may also be due to your having made the sodium salt of the proteins.

Simply reconstitute the PPT in a suitable buffer, transfer to a sterile 10 kDa cut off dialysis bag and extensively dialyse to remove salts and small molecules.

Alternatively, If you have access to Sephadex G-10 or G-25 column, perform rapid dialysis of reconstituted protein ppt.

SDS is the most powerful solubilizing agent (obstacle) of your buffer against taking the proteome out of the solution. I do not know if UF is fancy or not for you but the most efficient way to get proteome with minor loss is the UF technique as physical treatment. Do not forget to add urea to disrupt SDS micelles prior to the UF process...Other than UF, you may follow the technique suggested by Adam B Shapiro...Simply dilute your sample by adding D.I. water and use either TCA, TCA/acetone or AS precipitation...Remember when you dilute the desiccant probably precipitated SDS will be dissolved and represents dissolved protein-SDS conjugates, it will coat your proteins and you may observe low recovery, thus I suggest the UF process...You may also look for The ReadyPrep 2-D cleanup kit which Employs a TCA-like protein precipitation to remove ionic contaminants from your protein samples....

You may also test meoh-chlorofom Folch precipitation method to get proteome as an interphase pellet...Alternatively, Trizol extraction could be beneficial...Trial and error-based approaches to get the highest recovery...