Yes, John. My guess as well. Below is the photo with a easier orientation for you to recognize, with reference points. I also am adding a photo of what the car looked like originally.
However, as this cabin heater is a post-Smiths, so the bulkhead intake cover likely rusted out and some owner replaced it with something (very well and likely homemade). The original manufacturer,was a Pecks cabin heater and they went bankrupt. Sadly, many owners (1987-1993) were convinced to replace their Smiths with a Pecks which didn't turn out well for them
but did for the Smiths crowd! That being said, earlier cabin heaters are a breeze (PUN!) to fix and even upgrade. The famous John Worrall used to sell a polished replacement. (also below)
Additionally, it looks like a non-original grid.
I don't use foam. One has two options to attempt to increase airflow. Either direct the incoming air from the louvres (and filter it) or leave it open. (shrug)
Lorne
![[Linked Image]](http://www.gomog.com/TEMP/heatercover2.jpg)