Waltham "1877" calibre

Hello,
Can anyone tell me if the 1877 calibre waltham had a breguet balance spring fitted to it originally?
I have looked in the data base and it tell me that the watch was made in 1882. (Serial N° 1741948).

The way the regulator pins and the balance spring are seems to me to indicate it was originally fitted with a Breguet, but some body has put a flat spring in instead.

[Tom McIntyre]

The 1877 model was developed with a flat hairspring in all grades. Some of the late Appleton Tracy & Co. grade were fitted with Breguet hairsprings in the mid 80's.

Here are a pair of them from each group.

Thanks Mr McIntyre for your reply,
I have one of the early ones, no jewels, and to get the balance spring to sit between the pins, I must shape the balance spring into a bowl! Otherwise it misses the pins entirely! The pins barely come below the bottom of the cock, and for a flat hairspring this is rather scary

I did once come across a balance spring that had the last 1/2 of the last coil raised. It was NOT a Breguet, just the last 1/2 turn was raised. I never could find out if it was a one off by a watchmaker or not but I suspect it was.
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[Tom McIntyre]

Is the regulator curved like the first example I showed? If so, either the regulator pins are too short, or hairspring is colleted too low, which probably means the balance is not correct, etc.

The regulator is exactly like the first example. The reglator pins are to short but they do not appear to have been shortened. This is what threw me. I would have to bring the balance spring up to the base of the cock to get it flat