It has been somewhat enjoyable seeing people calling each other names in a very civil fashion (and most likely reading each others posts in mild disbelief).
There is a chance that we may all be correct (and/or are understandably confused).
Check out 16.742 PANEL Top-Lining, (Fiber Board) (in the Master Parts Catalog).
1954/55 is of course a different part number (due to the front windshield change); however, there are three different earlier combination of roof liners: 47-50, 50-53, and a center-rear panel than changed sometime in 49-50.
Look at the note below that section: installation from front-to-back OR from back-to-front changed sometime in 1950.
Now, let's see if someone can find a listing in the MPB for the bows/retainers?