Which turntable should I keep?

After inheriting much of my Dad's classical and jazz lp collection, I've decided to rekindle my interest in vinyl. So I've pulled my old Thorens TD 145 out of storage (Stanton 681EEE) and found the box with the $10 garage sale Denon DP-51F that I bought just as it was about to find its way to the landfill. I haven't kept up with turntable and cartridge developments for the last 20 years, so I'm not sure which of these to use, or if I should buy new? The Stanton has about 7 years of moderate use on it, so I don't know if I need to replace the stylus. I've googled both of the turntables, and haven't learned much except that it seems that I should have ponied up for the TD 160 way back when. Haven't seen much on that Denon model, so I don't know if it is low or mid range equipment. I know that I've been pretty gentle with the Thorens, but don't know anything about how the Denon was treated. Its cartridge is a tan Grado with the marking GF 1? on its front. Any suggestions on what I should do? Modifications, upgrades, new purchase? Which cartridge is the keeper? Or should I buy new?
Keep both TTs.
You will change the cartridges of course.
You will also end up changing tonearms.
You will probably have to overhaul them, too.
All of the above are CHEAP and fun.

There is a lot of documentation on the Thorens that can guide you in tweaking it (google it; google the DP-51F too). Cheers
Start with a cartridge replacement. The suspension has stiffened over the past 20 years, and there have been significant improvements in design and materials. Using a 20 year old cartridge is like driving a car on 20 year old tires. You are headed for a flat keeping with the old ones.
For the paltry money you have in these turntables, keep them both.

They are both good tables, but the Thorens may prove the better of the two. But the Denon is one of the better direct drive tables from that era, and is a good performer in its own right.

Replace the cartridges, and play them both to see what you like best.
What they said, and the TD145 is simply a semi-automatic version of the TD160, so basically you already have a TD160, with some convenience thrown in. I recently set up a Stanton 681EEE for a friend and was very impressed. So much so I ordered one for me!
you might want to change cartridges before playing your lps - it the cartridge is worn and/or the tracking force is too hight you could damage the lps
Try this site for Thorens information and upgrades:

The 145 would make the basis of a much better turntable. Build a better plinth, add a better tonearm and cartridge, and you are off to the races.

The Denon I would sell. It is a complex little thing with its servo arm. When (not if; it will fail eventually) it fails you will find parts very difficult to acquire. I owned a DP47F for sometime; liked it but sold it as I did not wait for it to get so old I could not recover my money.
A basic belt drive turntable is about the most reliable device known to man (and woman).
I agree with C123666. I had a DP45F, it could not be repaired due to lack of parts. I then purchased a DP51 from the repair shop. It died within 2 weeks. The shop gave me my money back. The parts for the servo arm are hard to come by.
many thanks to everyone. any idea what cartridge match would be best for each of these in the $100 or less range?
thanks for the link - my message crossed yours - I just looked at the site, should give me a food start. what is the plinth? is it what the tonearm is mounted to?
If it were me, I would keep both tables-- both are good from an era gone by---

I only wish I had your luck!@

welcome to the world of vinyl -- although jazz and classical are not my venue of choice, seeing the tables that your dad had, it looks like you might have a pretty nice LP collection as well!

Not to be redundant with others --- invest in a record cleaning machine !

Welcome to the fantastic world of vinyl !