[R-390] Curry 6 kHz Filters for R-390A

[KK4XO Gmail]

I’m looking for a 6 kHz filter to use in the 16 kHz filter position on the R-390A.  Dave Curry (Longwave Products) apparently manufactured them at one time and the website is still there ( http://www.75a-4.com/ ) but I just had a letter returned from the P.O. Box address given.  Come to think of it, I’ve not seen any mention of his products for the past six years or so and I’m wondering if he might even still be in business.
Does anyone have any current info and/or a spare Curry 6 kHz filter to sell?
Thanks,
Bill, KK4XO