Yotems, it's nice to hear from another NEC fan! I agree with much of what you say - up to a point. I've been a big cheerleader for MCS gear here on AK for years, and I collect that brand along with NEC gear.
I have owned the Taiwan stuff, and, while it's build quality is lower than the NEC stuff, it's still fine gear for it's price point. Check ebay and you will find many Taiwan pieces still in service after all these years. That should underscore their quality. Sear's LXI brand certainly can't compare, yet many people still lump MCS and LXI gear into the same group - low end store brand junk. Ok, they think that until they find (and listen to) some MCS pieces - LOL.
And yes, no MCS receiver was ever made by Technics. I've tried to tell people this for quite a while now, but it's a hard habit to break, I guess. There is the MCS 2500 receiver - a rebranded Panasonic, but technically, not a Modular Component Systems piece. It's MCS stands for "Matched Component Systems". Their Taiwan made units were not made by Technics - they were designed by Arvin Electronics in the US, and manufactured in Taiwan.
NEC got into home audio right about the same time Penney's started contracting with them - early 1978. For proof, I once found a MCS 3275 receiver that was a mock up model for Penney's buyers to see. On the back panel it still said NEC instead of MCS, and it had hand written labels for the adapter input and output jacks. It was the very first MCS receiver made by NEC (a rebadged NEC AUR-8075), and I regret not bidding on it. It was a sample unit that never made it to the sales floor, so it was unique. So, IMHO, NEC came first, and MCS came right after it. Curtis Mathes started using NEC as a supplier in 1981-82.
Any NEC made gear sold in the USA will have NEC codes on the circuit boards, and the NEC factory code on the rear panel. The circuit board codes will start out with "YEC-##-####". Their factory code was "720", and will either be silkscreened on the rear panel, or be a sticker. Sometimes the 720 was followed by one or two random letters, but the 720 is the giveaway that it came out of NEC's Tokyo, Japan factory. There are a few exceptions to this. The first few months of NEC production used hand written numbers on the circuit boards (in black magic marker), and no 720 label on the rear - the codes and 720 appeared a few months in. Also, the MCS 3040 10 band equalizer has no manufacturer codes on it at all, yet it was made by NEC (the service manual says so). This is most likely because the 3040 EQ was also sold as the Yamaha GE-3, and Yamaha probably didn't want any identifiable markings on it. That makes sense - if people found out the Yamaha was also sold as a MCS (for less money), Yamaha's image may have taken a hit.
Check for NEC factory codes and circuit board codes on other brands of gear. NEC made gear for other brands - including Nakamichi.
I also am one of those who feel like the MCS 3125 is one of the best sounding receivers of all time. It simply blows away all my other receivers. The 3285 does indeed have nearly the same amp section as the NEC A820, but their preamps are so different, that the two units sound VERY different. The A820 sounds closest to the 3125, and the 3285 sounds closest to the NEC A-11 (and it's brothers -the A-7, and A-10II). I know that may be hard to believe, but that's what my ears tell me, so it's only my opinion. Compare them for yourself, and form an opinion. The 3236 I had did sound very nice, but it was no where near the 3125 in sound quality, IMHO.
I've complained about the Vintage Knob site saying the 3285 was made by Technics for some time, and I think Axel changed the text a bit, but still clings to the notion that Technics had a hand in it. I don't know why he assumes this - although all the other SeriesA components WERE made by Technics. No MCS catalog or brochure ever stated who made their gear, so he is simply assuming the 3285 also came from Technics. It's so easy to prove it was made by NEC.
JC Penney had a tough decision when deciding who made their MCS gear. NEC as a company would NOT build a low quality item - their quality standards were very high. That came at a cost, and Matsushita could supply them with lower cost gear. Penney's paid a dear price when they switched from NEC to Matsushita to supply them with their higher end integrated amps and tuners in 1983, 1984, and 1985. The models produced from those three years are nearly all in landfills somewhere. They had a very high failure rate. Penneys went back to using NEC in 1986, and their 1986 and 1986 1/2 models were of very high quality, and ebay has a ton of them. After the 1986 1/2 model year, Penney's caved in, and stopped using NEC altogether. Starting in 1987, Matsushita was back as the main supplier, and the quality went in the dumpster. Curtis Mathes still continued on using NEC rebadges through 1988 or so - selling a few of their surround sound integrated amps and receivers. MCS never got into surround sound with any gusto, so they slowly went away. By the mid 90s, MCS was gone. My "newest" MCS piece is a CD player from 1992. An entry level model, and I have no idea who made it for them, but it sounds okay and works well.
Just my 2 cents....