Worth repairing a Velodyne ULD-12 from the 90's?

Probably not and besides, most all the new subs come with an app that makes setup a breeze.

All the best.

@waytoomuchstuff You mean that multi-purpose spray cleaner or a big block Chevy...?

there is a place in new jersey that fixed my servo board on my uld 18mk2.

https://www.ebcelectronics.com/

I have the ULD-15, a MK I and a MK II. 

On the MK II, the foam fell apart. 

I bought a kit from these guys:

https://www.springfieldspeakerrepair.com/collections/diy-foam-surround-repair-kits

It was far easier to do the repair than I imagined it would be, as the cone tends to just center itself.

It works like new. 

I recently had my DD18 repaired, had to have the amp rebuilt but it's back and as good as ever.  Glad I did it.  It was a few hundred bucks but it'd be very expensive to replace.