The original MK-52 came with memory expansion modules, called "BRP". I have never seen one in-metal, but by the effort of Sergey Frolov the contents are available for download at http://www.leningrad.su/museum/show_calc.php?n=157

The "disassembler" program was provided by Mike Yakimov at https://github.com/myak555/MK-52_Resurrect/tree/main/MK-52_Sample_Programs/BRP%20Expansion%20Modules

The extraction of the first 5 programs (out of 60) from the BRP-3 image went without a glitch! The translated manual is here:

https://github.com/myak555/MK-52_Resurrect/wiki/12.-BRP-ROM-Instructions

Instead of the bulky BRP, the programs now are kept at the SD card. For what I understand, the module insertion into the calculator was a tricky business.

The plan so far is to convert both BRP-3 (math programs) and BRP-2 "Astro" (navigation programs) into usable form.