I have an old HHB Portadat with TC that's not used.
I used it mostly for location work and game sound recordings 6-7 years back but now I haven't touched it for a long time.

Is there any use for it in your opinion?
It performs nice but as most I do today is run and gun I can't see it being used again.

First I thought that perhaps I could use it as a preamp with TC and add an electrical spdif recorder on the output but I don't know if that's just impossible and to much hassle anyway.

Any thoughts?
Keep it in case or sell it cheap?

A friend of mine uses his old Nagra's on the book shelf as book ends......

I have an even less capable portable DAT deck than yours (no TC, no phantom power). The only use I envisioned is exactly as you say, for the preamps and digital conversion. At this point though I should probably sell it, along with the still wrapped DAT tapes I have. However, I could see it choking the first time someone attempted to record with it and me having to refund the money. I don't miss tape!

Mine makes a good paper weight and takes up unused space in the attic.

An excellent machine in its day and probably still very usable.

But has no second-hand value now.

I would keep it for replaying old DAT tapes.

I still have a pair of Fostex D-10 DAT recorders and those were £2k + each when I bought them!

As I thought then :)
It's still sexy looking and works perfect so I'll rather keep it then bin it.