Is it possible to tell the aproximate date of a speed by differences in its appearance? I know that the all black ones are from the second world war era. I do not know how to tell an anniversary from a preanniversary, ect.. In essance are there distinguishing characteristics that would allow one to roughly date a speed graphic.

Ahh a "Field Spotters Guide To Graphic cameras" eh? Well you can take a gander at the rest of the website under speed graphics. It may take a few clicks and flips but there's a tremendous amount of info there. A soundbite version would be

Top Handle speeds, have their handle on top (unles they've been modernized)

Pre Anns are grey and have a flip up sport finder with a round top section. both of these have a pinch type lock on the front standard (you pinch it to release) Most will have a wood web on the standard

Anns are chrome except those from about '43-'45 and have a rotating release.

Pacemakers have a brushed aluminum look used metal boards and have a side body release.

within that there's a myriad of subspecies and variants. But this will allow you to identify 90% of whats on ebay.