When expressing an Interest in Vintage Japanese DD TT's, there are two ways to observe them, which are loosely described below:
1, Is the observation through 'Rose Tinted Glasses' where the assembled product with a unknown hours of usage life of close on 50 Years is not considered.
An individual is somehow missing / avoiding what a 50ish Years in the real world can mean for a TT's Electronics and Mechanical Parts.
2, The Link will show an individual a good insight into what is being bought into, the Link is representative of most Vintage DD TT's to be seen on a Shortlist.
Mechanical Parts are limited and the Electronic Parts are quite substantial and quite complex.
Mechanical Parts can have had way too many rotations where critical parts are functioning in a non ideal environment, where a minimum negative effect developed is that the axis of the Spindle may not run true, creating a eccentric rotation and speed fluctuation.
Furthering regular usage of a TT with an eccentric rotation in a non ideal environment can lead to excessive wear on a sacrificial part such as a Bush. The excessive wear of a Bush/Bushes can result with a scribing showing on other Sacrificial Parts or even worse, scribing can show on parts that should be a Polished Finish, where scribing that has developed is most likely caused by metal particulate from worn Bushes being encountered in a very dry shaft with all signs of Factory applied lubricant long long dried up or leached from the Bearing Housing the Bearing Housing many many years passed.
Good Luck with the Electronics being Top Drawer, I only know Specialists who can comment on this when they have the TT on their Workbench.
The reality for quite few TT owners of all types from this period is commonly as follows:
I bought a Vintage TT, I Powered on and it rotated, Eureka, I have a perfect TT.
I'm looking for the Perfect Tonearm for my TT, after a Hum and Ha, I've just bought a TA at £2K - £3K - 4K for my Perfectly Working Vintage TT.
I'm now looking for a Cartridge to mount on my TA to get the best out of my Perfect Vintage TT. I am now the proud owner of a £2K - £3K - £4K Cartridge.
My take is use others known for their knowledge on a particular TT, to inform if the Vintage TT is a Perfect TT. Once this is a done deal, spend however one wants on how the other ancillaries are chosen to be used with the TT.
http://amp8.com/amp-etc/record/denon/dp-80-3.htm
For the record, all owned TT's are from a Vintage Period and ones Vintage DD ones used daily are brought to a fine fettle, by an individual who knows the Brands very very well and are reputed for their work undertaken. Both Bearing Condition and Overhaul and Electronics Function are addressed when on the Workbench.
The extra outlay for the TT's is a monies very very well spent.