Every workman, laborer or other person who shall do or perform any work or labor, for an incorporated company doing business in this state, by virtue of a contract either directly with such incorporated company or with its general contractor, or with any subcontractor, shall have a lien for the value of such work or labor upon all real estate and personal property of such company; and, to the extent and value of one month's such work or labor, said lien shall have priority over any lien created by deed or otherwise on such real estate or personal property subsequent to the time when such work or labor was performed: Provided, however, That there shall be no priority of lien as against conditional sales of, or reservation of title to, machinery sold to such company; nor shall there be priority of lien as between the parties claiming under the provisions of this section.