My DL-1 saddle when I bought it:



I discarded the old cover, got some sole leather about 3-4 mm thick, cut a square oversize piece and soaked it in wather for 15 mins. Molded it by hand over the frame (took me some time and force, about 40 mins, since the leather tended to return to its flat shape). Let it dry overnight and trimmed it to shape. Got some hollow copper rivets from an auto clutch and brake shop, punched holes in the cover and put the rivets but not hammered them yet. Did the final trimming and hammered the rivets on. Rubbed some linseed oil and let dry. The shape was OK, but the leather was too soft and sagged after some riding. Took the saddle off and soaked it in boiling water for 4 mins. When dry it was very hard and worked ok since: