Champion Transtar was a series of van conversion motorhomes, some widened body, from the 1980s. Your best connections here may be the "B" motorhome - van conversion forum.
My connection with the Transtar is peripheral. One of the couples in our RV club found that they could no longer handle their big fifth wheel trailer after he got his head trampled by an angry cow, leading to a progressive dementia that eventually took his life. Trading the trailer for a 25 year old Transtar kept them coming to club campouts for another year, because she (recovering from stroke) could drive it, and setup was not much more than parking it. They left the bed set up as a bed, dined with the group in the club rooms, used campground restrooms.
Some folks have a problem with the 6.2 diesel, and I personally would rather havevthe 350 V8 in a Chevy van of this era, but I had a colleague who would have nothing other than that diesel.
To post pictures, they have to be hosted somewhere, you imbed a link, and limit the display size. Except for signature blocks, you can't imbed images in your posts.
There is a forum about using the forums called "Forum Technical Support." Technology here is sort of primitive, but because it is prmitive, it is mostly safe and reliable, though often slow.