Hello Charles-san,

I'm a Japanese old HEUER lover and am new to this forum. Sorry for my late response because I found your post "Heuer Model 3000 Auto Chronograph" yesterday.

I have exactly the same watch you have(see attatched photo below). As Chuck Maddox-san had stated, the watch have a LWO283 in it.

To my knowledge, LWO283 is a separate module type chronograph movement which was originally released in May 1983 on HEUER 2000. The development was done by a collaboration between Lemania and Dubois Depraz. This development had started at 1979. Dubois Depraz calls this monumental chronograph module "DD2000".

I think the LWO283 is basically consist of:

Engine.........................................ETA 2892

Chronographe module...........DD2000 or its variation

One more remarkable point of this module... The DD2000 modules also can be used on some QUARTZ movement. For example:

LWO283...........DD2000+ETA2892(mechanical base movement)
Normline.........DD2000+ESA555111(Quartz base movement)

That's why HEUER had two identical-dial-designed chronographs, one is automatic, another is quartz.

At first, DD2000(LWO283) was to be used exclusively by HEUER. That was the contract by Lemania, Heuer Leonidas and Dubois Depraz called "collaboration triangulaire". BUT soon Heuer was about to bankrupt, and TAG came. TAG abandoned the exclusive right for DD2000(maybe for its high contract money, I think). So Lemania asked the other brands to use LWO283 or DD2000. This was the beginning of today's separate module type watches which are popular and essential(especially for the complicated chronographes).

So I think the model 136.006 is one of the monumental HEUER of that period.