I don't think it is one of the microfilms in the data sheet linked above. I do not believe they are perforated. I have some of the 2462 Duplicating Microfilm. It has no perforations, is yellow, and has a perfectly clear base once developed. The other two films on that sheet are direct-duplicating; they'd not the give OP a negative. Also, the OP's images don't seem have the contrast of microfilm.