The technique I use for rolling sheets of putty to a desired thickness could also be used for "sausages"....
I use two note books, using the required number of pages to get the desired thickness, placed either side of the putty, and use a length of 22mm or 10mm copper tubing to roll out the putty, rolling until the tubing is in contact with the note book.
Swapping the copper tubing for a flat tile will allow you to make even size "sausages". Just a matter of moving the tile back and forth till the tile is in contact with the note books.
The good thing about using note books is that you can make any thickness. And as a bonus, you can make a note on the page used, just in case you need to make more "sausages" of the same size in the future.