NavList:

I recently picked up on ebay the following slide rule. It is 10" long, with what looks to me like an unusual scale arrangement.

Reading from top to bottom one side at a time, the following is the arrangement of scales: LLO, LLOO, A. On upper fixed part. On moveable part B, K, L, C. On lower fixed part, LL3, LL2, LL1. On  the reverse side, the following scale arrangement. Upper section, T, and DF. On sliding part, CF, CIF, CI, C. On lower fixed part, D, S, ST. Usually, the trig scales, S, T and ST are grouped together, not so here.

The slide rule is marked Made In USA, no makers name in view. The thing itself seven for a used slide rule, appears to have had rough usage, though it is readable and so far as I can tell, it works. Any ideas on or about this creature, and what seems to me to be an unusual scale arrangement of trig scales.

Thanks for your attention and any response.

Alan