Mike, neither front nor rear tires are Pegasus...the rears are unknown (Corvette?) Goodyears, size 335/35R/20 from the parts box, and fronts are from the Cuda kit for the 'custom wheels'.
Guys, I've played around with the remnants of the kit lid that I cut free, and also the optional top from the Challenger kit Roger posted a pic of, and both would require tons of work to look like a softop. I think either modifying an existing convertible uptop or scratching one as Roger suggested would be the best option. An uptop for me is not a deal breaker, it looks good top down with a boot too
Thanks for the continued interest everyone, hopefully I'll get some progress over the next few days...