Of course it's for an SVT40- I shoulda known that. What happened was that I pulled the flash hider assembly, which is also the cleaning rod latch, to avoid any possible problems with some over-zealous Kalifornia DOJ type (the flash hider could be construed as being one of the features that makes it an assault rifle), and forgot about it. Ah, the joys of old age.
Anyway,my thanks for the input, guys.