Couple of comments;

- The pins/clips that I believe that you are referring to are pretty much standard aviation hardware. If I remember correct I used AN416-2 hardware. The diameter of the pin to fit into the hole in the L'Hotellier push latch may need looking into.

- As you are trying to feel your way to inserting the pins/clips within the darkness of the turtle deck void there seems to be a vortex that sucks these items into the belly of the beast which are then lost forever (or at least for a fortnight). Greasy fingers don't help. Ask me how I know. HINT: Tie a strong thin "lanyard" to each item to prevent this curse from befalling you.

The alternatives are to try one of the other types of L'Hotellier safeties list below;

1) For once-a-season rigging of a glider the use of aviation safety wire is perfectly legal.
2) The Schleicher "pin" as mentioned above. This stays in place on the L'Hotellier fitting. Simple and "aviation cheap". Unclear to me how these are initially first installed (versus used) - does a second hole need to be drilled into the body of the cup end?
3) A nylon "Eurling sleeve" AKA "LS Safety Sleeve". Tough to find these days it would seem. I believe that they only work on straight L'Hotellier fittings not the 90 degree kind. Also, I was told that these need to be replaced every X amount of time. YMMV.
4) A spring loaded "Wederkind" sleeve. I installed those on my old DG-101. Bought them from a dealer in the UK. Loved them. Very simple to use. The installation details and sources can be found at http://aviation.derosaweb.net/wedekind/.

Best of luck;

- John OHM Ω