The 60s we have pretty much covered in the catalogues section; Heuer majored on chronographs in this decade (after stopwatches of course, which was the majority of the business).

The 50s does seem to be something of the lost era of Heuer watches; I certainly have less knowledge of that decade than the few preceding it and of course the much better-known couple of decades following it. We have seen a few 50s era watches here on the forum - many of them, if not even most of them, have been time only.

The most you'll find on the 50s watches tends to be on one of OTD's contributors, Jarl's, website, like this one on a simple automatic:

http://classicheuers.blogspot.com/2009/06/1950s-heuer-automatic.html

It's important to remember, though, that by modern sensibilities Heuer (when it was Heuer, rather than when it became TAG-Heuer) never made what we would consider a lot of watches. Certainly not in Rolex volumes. But exclusivity doesn't necessarily equate to value every time - these seem to have settled between the £200 and £400 marks, a decent increase over the original purchase prices sure, but nothing compared to what the later chronographs are achieving now.