As well as what Dick has suggested, you need to confirm that your output will only be for matches on the key.
If this is so, you need to find a JOINKEYS example. If it has a JOIN, remove it (so you only get matches). You need a REFORMAT statement. You can include on that, in the order which you require for output, all the F1 pieces of data, intermingled with the F2 pieces of data. That should nearly do it. Where you need the blanks, just include five bytes from F1 or F2. It doesn't matter what they are, as you will make them blank.
You make them blank in the "Main Task", after the JOINKEYS statements and the REFORMAT.
Use INREC OVERLAY=(pos1,5,C' ',pos2,5,C' ') or however many you want.
Have a go, and let us know if you encounter problems. Show us what you have if you get it working, and we can check it over.