I simply reused my leather too. If your leather has worn through, you might be better served by finding a good pice of trim from a suitable donor car. This will allow for a much closer match in color due to sun fade.
As far as the adhesive goes, spreading it thin with a piece of cardboard left the adhesive fairly smooth. This stuff is contact cement, so you are limited in the number of passes you can make before the cardboard starts to stick. I pretty much stuck to using two passes while the glue was still very liquid.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.