The Q&TL 6 could be restored but as someone who spent 5 years restoring an interuban and only got 1/2 done, the amount of the work is considerable. The real question is the condition of the boiler which maybe one of the NJ guys could answer. Most museums have more projects than money and volunteers and that may have had something to do with the decision not to undertake any restoration.
As to never say never, in 2003 I visited Minersville, PA and looked at at an ex CNJ 0-6-0 undergoing restoration. I thought it would never get finished. Guess what? It is now under steam and operating.