I don't have a recipe but, if you are referring to Ry Krisp Brand
Cracker, made by Bremner, I do know they are still made
<http://www.bremnerbiscuit.com/RyKrisp.htm>. They are readily
available in grocery stores here in the St. Louis area. Just a week
ago I purchased a box and selected the Light variety from a choice of
Natural, Sesame and Light. The sole ingredients in the Light variety
are whole rye and salt. The website says twice baked, so I think the
Light variety would be very easy to duplicate with a little experimentation.
You might consider contacting Bremner to identify where they could be
purchased in your area. There is a link on their website to order
for mail delivery.