Police released the CCTV images, which can be seen at here, to help in the investigation of the robbery at Banwell Antiques in Honiton on Saturday, March 22.
The incident took place as the woman, who was working alone, opened up the store at around 9am. She was grabbed from behind by the suspect before being tied up. Although not physically injured she was left very shaken by the incident and is now being supported by officers and her family.
This footage shows the moment the man entered the antique shop and grabbed her from behind.
Det Insp Charlie Craig said: "Although we have followed up a number of lines of enquiry, we still do not know who this man is. He may not live in Devon and Cornwall so we are urging people to share this footage with friends across the country, using social media, so we can find out who he is."
He is described as white, of slim build, unshaven, with short dark hair, and is aged 30- 50. He was wearing a blue coat, blue denim jeans, black trainers, beige-coloured flat cap and was carrying a blue rucksack and black holdall bag.
Although the value of the items stolen has not been fully assessed, police know the quantity and quality of the jewellery taken was considerable.
Anyone with information should contact Devon and Cornwall direct on 101 quoting police log number 467 of March 22 or to give anonymous information contact Crimestoppers on 0800 555111.