Yes, that's about it.

My stance is that 348 is the H.O., T-42/611 is a value added option that creates a Ram Air car. What all the components are in the Ram Air package, I do not have supporting documentation. I will check the Assembly Manual for a breakdown.

I have the same images shown early in the thread, I can get all but the last two digits of the obscured VIN. Looks like 223379L114297 on the first RA. The second one I can't see anything. The first HO is 223379N101278(or 9). Next HO is 223379U1143xx. Then a RA convertible 223679Xxxxxxx and the Export HO 223379N103xxx. There were likely others in there I missed...

Price changes during the model year are common on the engines, where the convenience and appearance options are relatively stable.

I don't feel comfortable plotting a trend with so few pieces of data, there MUST be more copies floating around...