Those reefing claws are getting rarer all the time. You might find one in a Marine Consignment store, or some sailboat dealer who has been around since the 1960's might still have one hiding in the backroom!
However, as one DS II owner to another, GIVE UP! You will not really be able to get a satifactory reef using the standard roller-reefing, I tried, and I was lucky enough that my DS II came with the Claw when I bought her used. After trying for 4 seasons to make the roller-reefing work (the boltrope on the sail bunches up and causes 2 problems, 1) the luff of the sail rolls in more than the leech, causing the clew end of the boom to droop, 2) the boltrope tends to prevent the gooseneck from springing back to lock in the reef) I finally converted to slab-reefing (or jiffy-reefing) by having a sailmaker install reefpoints in the sail. Cost was around $65 in 1999, I added some hardware that cost around $40 - $50 and can now reef the sail FAR better than the original roller-reefing could. Plus, I don't have to disconnect and reconnect the mainsheet each time, and the slab-reefing still allows me to use my boom-vang while reefed, the roller-reefing prevented that since hte sail was covering the fitting on hte boom that the vang hooks to. The Vang is most important in stronger winds as it helps to flatten and de-power the sail reducing heeling of the boat. The Vang also reduces tha load on hte mainsheet since it holds the boom from rising up as you let the sail out. With hte vang you are only moving the boom in/out not down plus in/out.
My $0.02
PS: I sold the Reefing Claw several years ago, so sorry but can't help you there!