I know nothing of Clamshells, but the Wallstreet has a charge card that connects to the logic board at the front of the machine, and it often goes bad. Replacement of the charge board is often mentioned as a potential cure for anomalies such as not recognizing a battery, not charging from it, and not running from a known-good one. I do not know the physical layout of your machine, or whether there is a separate charge card, but two thoughts:

1. Have you checked that the battery is actually making a good physical connection with the charging circuitry—that the wires are present and accounted for, properly aligned, and that solder joints from the connecting "springy wires" to the board are good?

2. It has been a while, but I do seem to recall that the charge card of a Wallstreet has a lot of capacitors on it. I suppose that one potential fix would be a caps job, but beyond this I am out of my depth.