The extra tiles next to the stage 1 and stage 6 backgrounds are extra pieces that are unused. The extra stage 1 tiles obviously would fit on the right side if the screen was wider, but the extra stage 6 ones don't seem to fit properly anywhere.

Also yes, the wonky tiling on the stage 6 image and the weird repeated ground tile on the stage 3 one ARE like that in-game. Zender Lion's silhouette happens to block most of the repeated tiles on the stage 3 one in-game.... but most of the weird tiling on the stage 6 one is still plainly visible even when the screen is fully assembled!

Also also, "Rescueman" and "Firebird" are alternate names for Time Patrol Otasukeman and Yattodetaman. They also appear on some pieces of merchandise from around the same time this game came out.