No person engaged in the business of dyeing, dry cleaning, or laundering wearing apparel, cloth or other articles, shall be liable, or in any action or suit against him be held liable, for the loss of, or injury to, any wearing apparel, cloth or other articles delivered to him to be dyed, dry cleaned, or laundered, in an amount greater than the purchase price minus depreciation of such wearing apparel, cloth or other articles, unless at the time of the delivery to him of any such wearing apparel, cloth or other articles, the value of the same, and when there is more than one piece or article the value of each piece or article, be agreed upon and evidenced by a writing stating such value, or separate values when there is more than one piece or article, signed by him; provided, however, that:
1. Nothing in this section contained shall be construed as requiring of any such person more than the exercise of such degree of care as is now imposed by existing law;
2. In no event shall any such person be held liable in any suit or action involving any such loss or injury for any sum greater than the damages suffered, and proved, by the plaintiff therein when such damages would not under the rules of law existing prior to June 18, 1920, exceed the purchase price minus depreciation of such wearing apparel, cloth, or other article;
3. Nothing in this section shall be construed as interfering with or inhibiting, or impairing the obligation of, any written contract between any hotel, railroad company, steamboat company or other patron and any person engaged in the business of dyeing, dry cleaning, or laundering of wearing apparel, cloth or other article, in relation to such work;
4. No liability shall rest upon or be borne by any hotel for any loss of or damage to wearing apparel, cloth or other article, the property of any guest of such hotel who shall have delivered, or caused the same to have been delivered, for dyeing, dry cleaning, or laundering to any person engaged in the business of dyeing, dry cleaning, or laundering.