I recently fell into (or fell over) a JRC NRD-515 receiver. One might argue it's a poor man's version of the Collins 651-S1, though these rigs always have commanded a decent price.

Mine's in need of help. The knobs look to be coated with many years worth of grud buildup, the RF band pass filter selection circuit (and possibly several band pass filter elements) aren't working properly. On the plus side, it came with the accessory filter board and the OEM 600Hz CW filter. The negative to that is the CW filter appears to not work. It's a Kokusai and their failure mode is well known - as is the fix.

Walt, PE1ABR has been helpful with troubleshooting and providing reference voltage levels in a working unit (he owns several of them). First order of business is to find out what's up with the band pass circuit, then on to the filter. I managed to find a 1000Hz JRC filter for the unit so it'll go in the Aux filter slot.

I'm tempted to mod this thing with a bunch of the more widely known improvements and a couple of my own thrown in for good measure. Such as an IF notch filter and a squelch. Cosmetically, the receiver is a very close cousin to the FT-901/902DM (albeit with black instead of gray knobs) and that's what I'll probably end up pairing it with. I had a chance to buy a complete 515 station (including the transmitter and station power supply) but that setup is a little too pricey at the moment...