I purchased my Boler
(I'm the third owner) and have some of the original documentation. The original label on the side indicates that it was built here in Winnipeg in February 1973 and I have the orignal warranty card indicating it was purchased by the first owner May 3, 1973.
It has the front refectors that are mounted in recesses and does not have the small window over the stove area. After seeing your post I looked at pictures of other 73 Eggs and none had the reflectors that I could see.
According to the information I have seen, the Boler
was being produced in several locations by 1973, so it is possible that there were some differences between plants or some changes were made throughout the production year. Looks like your previous Boler could also have been a '73 as it sounds just like mine (except the colour...mine is green on the bottom)