Peruvian crowns, both from Spanish colonial times and from after independence, were popular media for counterstamping by other countries. The following is a 1834 Peru 8 reales, which was counterstamped in 1840 for use in the Central American Republic (Guatemala).
Guatemala at this time (1838-1840) was in civil war, the result of which was termination of its union with other central American states, a confederation which existed only briefly in the 1820s and 1830s. Coins, however, continued to be minted with the emblem of the Central American Republic, only featuring the name 'Guatemala' starting in the 1850's.
Host: Peru 8 reales, Lima mint, 1834
The counterstamp is essentially a 'Type III', which is recognized to have been placed on coins in the year 1840. The 'obverse' of the counterstamp features a profile of three volcanic peaks, a cloud, and a sun, much like the design on the official Central American Republic coins (which were also being minted in Guatemala at the time). The stamp has a nice die crack.
The 'reverse' features another sun, bow and arrows
What makes it a Type III stamp is that Type I and II feature only the sun and volcano stamp on one side of the coin. Type III features the two stamps on either side, but impressed separately (note they occur at different locations). Type IV, issued in 1841, was both stamps impressed with a hinged pliers that punched the two simultaneously and thus in the same location on either side of the coin.