I found a thread
that had the photos seen here, and there are a few others- but there's just not an abundance of info on these trucks.
Seems there was the pace truck and also a LeBaron pace car that was also used at the Indy 500 in '87. It also seems from the thread that there were two versions: Trackside (top) and Streetside, shown below. I don't really see how the streetside version is a replica, though- no Indy 500 graphics anywhere to be seen, and quite a bit different than the one w/the Indy 500 graphics... but in any event, it is (or they are) rare.
Whether or not rare will ever equate to rare AND valuable, who knows. But I would keep it as original as possible because if it's going to have any real value to a collector, it will be as an unmolested original and not as a modified/hotrodded example, IMHO.