A mechanical apparatus for modifying an individual sheet feed offset duplicator to print impressions on continuous form pre-punched and perforated paper. A first tractor module is attached to the input of the duplicator for delivering the paper into the duplicator and an indexing mechanism is provided in the first tractor module for providing precise indexing to the paper as it is delivered into the duplicator. A device for adjusting the registration of the impression on the paper is provided in the first tractor module adjustment while the machine is operating. A rear tractor module is also connected at the output of the duplicator and engages the continuous form paper to maintain a predetermined amount of tautness on the paper by providing supplementary pulling on the paper while the paper is pulled through the duplicator. The present invention can also be used to collate multiple streams of continuous form paper into a single output stream as part of the printing process. Adhesive is then applied to the lateral edges of the output stream to create multi-part forms.