A fantastic piece! Based on the images you provided, here is a description, history, and valuation estimate for your Junghans Astra Shockproof 7 Jewels Pocket Watch, along with a guide for an eBay advert.
Your watch is a Vintage Junghans Astra Shockproof Pocket Watch, likely dating from the mid-20th century (approximately 1950s - 1960s).
Brand and Model: Junghans Astra Shockproof. "Astra" was a model name used by Junghans, and "Shockproof" refers to an early form of shock protection for the balance staff, a common feature on watches from this era.
Dial: The cream-colored dial features a mix of Arabic numerals (at 3, 4, 5, 7, 8, 9, 10, 12) and applied or painted baton/line markers (at 1, 2, 6, 11). It has a sunken sub-second dial at 6 o'clock. The markings clearly state "JUNGHANS ASTRA SHOCKPROOF 7 JEWELS" and "MADE IN GERMANY".
Hands: The watch uses "syringe" or "leaf" style hands for the hour and minute, and a simple pointer hand for the seconds sub-dial.
Case: It is a hunter-style pocket watch case (meaning it has a hinged front cover over the crystal, though yours appears to be open or has a missing/removed crystal cover, but the movement is accessed via a hinged back). The reverse of the outer case has a simple, engine-turned or lined decorative pattern with an unengraved rectangular space for initials. The inner dust cover is plain. The case is likely chrome-plated brass or stainless steel, common for utility watches of the period.
Movement: The movement is a manual-winding, bar-style caliber (a type of movement bridge design). It is marked with the Junghans eight-pointed star logo and is specified as 7 Jewels. Historical Junghans documents suggest a 7-jewel pocket watch calibre used in the mid-century period could be related to the J38 Astra (produced 1926-1953) or similar Lépine-style calibers of the era. The presence of a shock protection system suggests a later production date within that range or a successor caliber.
Junghans: Founded in 1861 in Schramberg, Germany, Junghans was once the largest watch and clock factory in the world (by 1903). They are a significant name in German watchmaking history.
Astra: The "Astra" line of watches, as well as the 7-jewel configuration, indicates a model aimed at the popular and utility market. A 7-jewel movement focuses on jewel placement at the most critical points of friction (the balance staff, pallet fork, and escape wheel), offering better longevity and accuracy than non-jeweled watches, but was more affordable than 15 or 17-jewel movements.
Time Period: The styling (numerals, hands, and sub-seconds dial) combined with the "Shockproof" and "Made in Germany" markings suggests this watch was likely produced in the post-World War II era, possibly in the 1950s or early 1960s, a period when Junghans was a major producer of both military and civilian timepieces.
Model: Junghans Astra Shockproof 7 Jewels Pocket Watch (Likely mid-century, c. 1950s-1960s).
Condition: Good vintage cosmetic condition, fully working, and keeping good time.
Estimated Value: In good working order, this piece would likely fetch between £100 and £180 (or equivalent local currency) in a private sale, depending on how quickly you want to sell and the specific material of the case (if it's solid silver, it pushes toward the higher end).
For Sale: A handsome and reliable vintage Junghans Astra pocket watch. This piece is fully functional and keeping excellent time, ready to be used or added to a collection.
Manufacturer: Junghans (Germany)
Model: Astra Shockproof
Jewels: 7-Jewel Mechanical Movement
Display: Analog time with a dedicated sub-second dial at 6 o'clock.
Dial: Light cream dial with clear Arabic numerals and baton markers. Shows light, attractive vintage patina (see photos).
Case: Classic hunter-style case with decorative engine-turned finish on the back.
Functionality: Fully Winding, Running Well, and Keeping Accurate Time.
Movement: Confirmed running strongly and keeping accurate time.
Cosmetics: Good overall vintage condition for its age. There are expected signs of gentle wear/age on the exterior case and light patina on the dial, which attests to its history. Please review all high-resolution photos carefully as they form a major part of the description.