It seems like the Conrad was never advertised in the newspapers while the Bertram is advertised since 19 November 1930, three and a half weeks before the Conrad appeared in the Saturday Evening Post ad of December. This leaves us to two options:
1. the Conrad is a yet to discover model that is similar, yet different somehow (single color?)
2. the Conrad and the Bertram are the same
I tend to believe the latter for following reasons:
a. it is not the first time that we see a name mix-up between newspaper and Saturday Evening Post ad, where the newspaper turns out to be correct. Indeed the name Bertram is consistently used during 1931 as well and Conrad does not appear at all in the newspapers.
b. Price of Conrad and Bertram is the same at US$57.50 and both are 21 jewels
c. dual tone was a new feature (as was 21 jewels). It makes sense that their most expensive model therefore would be two tone. If the Conrad was the single color version, why still have a single color for your top model at the same price?
d. Also the Gladiator was advertised without mention of "two-tone", nor pictured with two colors, while we know it is. The Conrad ad is in the same format as the Gladiator ad, so still could have been two tone.
A Bertram it is.
By the way, it is the first 10AN 21j. I found. The Tyler (21j version of President Madison), used the 9AF.