Ancient footed crystal glasses with relief twisted fluted goblets.

Here are 5 very beautiful and original crystal glasses with their flared chalice adorned with twisted ribs (relief twisted flutes) and their intricately worked stem. They have a stamped engraving underneath at the centre of the foot (difficult to see at first glance, it requires the right angle of light, but does not seem to be present or visible on one of the glasses). Despite extensive research, I have not been able to identify which crystal factory they come from, although the stamp is quite "understandable" (3 Cs around a circle and the mention "Cristal"). Therefore, further investigation is needed, and if you know more than I do about these glasses and this stamp, I would be delighted to learn more. In any case, it is the result of very fine craftsmanship, as evidenced by the minute differences between them, which are not visible but can be detected by the difference in weight. Indeed, they weigh between 156g and 184g, which is heavy for their size. Their capacity seems more suited for digestifs, a bit small for wine glasses. Without further information, it is difficult for me to date them, perhaps from the 1930s. They measure 11.5 cm in height and 6 cm in diameter. They are in perfect condition, neither chipped nor cracked, not even a scratch.