My understanding is amonia is present mainly in younger stages of a cigar's development. It has however been said to sometimes return (generally in much softer /lighter aroma than the phenomenon that occurs when young), suggesting that cigars may go through what one enthusiast described as vacuum periods, others sometime use the term sick - All of which sort of overlaps as there is no concise definition to rely on with regards to any of these theories or the terms used to describe them.

Cigars during the boom period were likely more prone to amonia because the tobacco was in such demand there was a loss of ability to age & treat tobacco to the extent that it had been prior to that period. Also keep in mind that Tubes are meant to slow the ageing (oxidization) process. So a tubed cigar would be more likely to display characteristics of younger cigars (such as amonia) than an un-tubed one.

Lastly there is also the sad possibility that what you got was indeed from the "boom" period and due to hurried or carefree production, the fermentation process was not carried out to the extent it should have been. If so, something like the amonia smell might be present an un-natural period of time, not to mention the over all quality of the cigar itself likely being suspect. When corners are cut, it often is not only in one direction. On the other hand, the tube is a mystery to me as that itself suggests the cigar must have had some sort of anticipated status unless it was simply a ploy to hide the physical characteristics from plain view. Unlikely if you ask me, the tubes cost money, and again, corner cutters usually go the cheapest and most unscrupilous routes.

Take one of them out of the tube for a few months and then light it up maybe comparing it to one that remained tubed.