Here's a copy of a post on a frame I reworked to fit a Shredder:
Last year I reworked one of my small-cat frames for a Shredder. Didn't get any pics, but she just dug it out of her basement and we floated some Class II for a reflex-check.
The boat belongs to Jodie Atherton, a former river guide with a ceramic studio in Laramie. It's a 1" ips steel double-rail with a drop footbar and a tramp seat (like the Cutthroat seats built by Jack's Plastic Welding) with a Jack's inflatable backrest. The oars are 7.5 footers. She thinks it needs 8's.
She had trouble finding partners for R2 paddling, and the frame turns it into a solo oarboat. It rigs to eight dees we glued on, so it's easy on and off.
The oarlocks seem a bit high to me, with respect to the seat, but she likes it so far. Anyhow, as frames go it's a pretty easy build and it turns the Shredder into a killer playcat.