Obverse Design Legend curving above says "ADMIRAL . VERNON . AND . COMMODRE . BROWN". There is an inside line enclosing the legend. Hip length (1/2 length) figures of Brown on our left and Vernon on our right are facing each other, both holding batons. Brown's head is beneath the . or space between "ADMIRAL" and "VERNON". Vernon's head is beneath the "OM" of "COMMODRE". A line cuts across the bottom of the medal. Under the line is an ornament of a convex (outward curving) shell with a branch holding two larger and three smaller leaves on each side.
Reverse Design Legend curving along the top says "WHO . TOOK . PORTO . BELLO . WITH . SIX . SHIPS . ONLY .". There is a line or ridge enclosing the legend. In exergue (under a line along the bottom of the medal) it says: "NOV 22 1739". There is an ornament of two stems crossed below the date. The center is the attack on Portobello. The six ships are lined up two in the top row and four in the bottom row. those below in a curve along the bottom edge. All ships are sailing to our left. No vessels or boats are in the harbor. A tower and two steeples point to the right of the letter "O" and at "W" and "T". There are faint water lines, hard to see. The forts on the right and left are large and have fourteen guns each.
Distinctions There are about 31 similar varieties with Brown and Vernon. Of those, about 27 involve 1/2 length Brown and Vernon's facing each other holding batons. So the varieties are hard to distinguish. It comes down to the legends and the locations of the spires, towers and steeples on the reverse. Seven of these medals varieties have the title COMMODORE misspelled as COMMODRE without the second letter "O". Of those, one other has spires or steeples pointing to the letters "W" and "T". That one, however has a tower pointing at "LO" instead of to the right of "O".
Detail On Obverse of VN-2.305 Detail On Reverse of VN-2.305
Detail of VN-2.305
Note the misspelling of "COMMODORE" as "COMMODRE".
Detail of VN-2.305
Note the tower and steeples at the letters "O", "W" and at "T".
Metal Brass and copper. Weight Unknown. Size and Shape Round, 37 mm in diameter.
Rarity Common. Designer or Issuer Not known. Other Catalog Numbers Betts #260, McCormick-Goodhart #153.
Notes Sales include a similar piece (exact variety unclear) in VG condition 'numismattic' sale on ebay to 'cwhiteloch@aol.com' (June 13, 2001 for $76).

The Customs House in Portobello shown below was used from 1630 until Panama's independence from Spain was achieved in 1821.

Customs House in Portobello
Customs House in Portobello
From the Canal Zone Review, Fall 1971 Edition