Victorian pendant locket gold guilloche Guilloche enamel landscape Swiss (7500)

Antique Victorian gold and enamel pendant locket.  Black and gold enamel and polychrome guilloche enamel. Almost certainly Swiss, made 19th century.   

Measurements: 
Weight is 8.6 grams. A tad over 1 inch in diameter (approximately 2.3cm). Approximately 5mm wide. Length of locket including the loop 1 1/2 inches (3.6cm). 

Description : 
An exquisitely enamelled round pendant case. Both top and bottom are enamelled: the back/bottom is engraved gold with black enamel in a delicate floral design of flowers and foliage. A central boquet of mixed flowers surrounded by concentric rings of various finely depicted flowers. Exquisite detail. The combination of black and high carat gold is superb. 
The top/upper outer case continues the black and gold theme in the subtle, narrow border. This also indicates that the parts (top and bottom) were originally made together. Within the outer ring of black and gold is a superb guilloche enamel depiction of boats on a lake, mountains in the background and a few building over to one side. The color range is beautiful - pinks, oranges and blues of the sky and sea with the black and gold shimmering buildings echoing the black and gold of the previous sections. Guilloche enamel over very finely engine turned gold. 
A glazed compartment contains a lock of hair. 
A ring allows a substantial chain to be attached to the case. 
Workmanship, as mentioned is excellent.   

Marks and Metal: 
The gold inside of the landscape has an engraved 1 and very lightly scratched numerals which were a previous owner's inventory number.  
Gold was electronically tested. In general, the gold is 18k, but the bow (loop), where it needs extra strength is 10k. 
     

Condition: 
We found absolutely no wear, loss or damage anywhere on the enamel.  Please see enlarged pictures and don't hesitate to ask questions which we will do our best to answer.   

THE STORY: 
Originally, we thought that this was a pocket watch case converted during the Victorian era to a locket pendant.  Upon closer examination and study, we came to the conclusion that it was always intended as a pendant. The glazed cover is very tightly sealed by minute screws that would not be convenient to access a potential 3rd section, were it a watch.