which of these files is the stock recovery image for the nexus 4 android 4.3?
Go for recovery.img. Extra info below:

bootloader-mako-xxx.img -> bootloader. Flash with fastboot flash bootloader bootloader-mako-xxx.img then fastboot reboot-bootloader. Updates (upgrade or downgrade) bootloader for compatibility with corresponding generation of ROMs.

boot.img -> kernel. Flash with fastboot flash boot boot.img or boot once with fastboot boot boot.img. Only use original ones or ones that are known compatible.