It does look like a cool cabinet... good candidate for a conversion...
My thinking on it would be:
It is YOUR cabinet... and you can do with it what you wish.
What I usually do with MAME conversions is try to be as non-invasive to the cabinet as I can, even if it is a generic cab... I try to make it a reversible conversion... even if I have to store some original parts, and make a new control panel or something...
If the artwork is in good shape, you can keep it on the machine...
Save the boards and harness for re-converting, selling or trading.
I do not know about the desirability of the TARG cabinet... maybe you could put it up for sale, and if someone wants it badly enough, or if it is collectible enough... someone will snatch it up for a good price.
It is pretty much up to you...