Peru, in my thoughts, was basically snoozing through the 20s, not overly concerned about world events other than wanting it's "stolen" provinces back from Chile. It woke up in the early 30s and saw that Chile was arming, Brazil was arming, Argentina was arming, and it wasn't doing anything. So it looked around for a supplier. It already used German small arms, so it went there to get more rifles and newer artillery. While there, it also contracted for a pair of DDs and a pair of ocean-going submarines to replace it's obsolete fleet of both types of ship.
Then, life got complicated: first, the SAE put up some ships for sale, light cruisers and destroyers, and Peru managed to snap up a pair of each. Then India put an ex-SAE dreadnought up for sale, and Peru was able to get that too (though it's still in India being refitted into as modern a ship as she can be).
All these purchases forced the slowing of the German purchasing efforts, but they continued at a slower rate, the last ships of the order will be finished pretty soon. At that point, Peru will be in possession of the plans for those types of vessel and the plan (of the preceding administration) was to build a number of those units domesticly before looking for much of anything else. Thought has been given to buying a number of 12" guns from the Phillipines for coast defence duties, and thought has also been given to having a second Lima class ship built (hypothetically named Cuzco), but neither has been contracted for YET.
If you want to PM me with your e-mail, I can forward the spreadsheet I'm using for Peru's planning.