Question Custom ROM for new device

Hi, I have new Prestigio tablet PMT5777_3G and I want to modify it's default ROM. I followed this tutorial: I successfully extracted system folder, but I have no idea how to create updater-script for this specific ROM. If I understand correctly I need to get updater-script from original ROM.

I've got something that resembles original ROM, but it's folder structure is completely different from what I would expect.
I would expect:
  • system
  • boot.img
I've got:
  • APDB_MT6582_S01_MAIN2.1_W10.24
  • boot-sign.img
  • BPLGUInfoCustomAppSrcP_MT6582_S00_MOLY_WR8_W1315_M D_WG_MP_V12_P4_1_wg_n
  • cache-sign.img
  • Checksum.ini
  • EBR1-sign
  • lk-sign.bin
  • logo-sign.bin
  • MBR-sign
  • MT6582_Android_scatter.txt
  • preloader_htt82_tb_jb5.bin
  • recovery-sign.img
  • secro-sign.img
  • system-sign.img
  • sro-lock-sign.img
  • sro-unlock-sign.img
  • userdata-sign.img

I'm an android developer, but have no experience with custom ROM's and now am in a situation, where I want to get that custom ROM up and running, but am unable, because I can't figure out how to create updater-script or extract it from files that I currently have. It would be great if someone could point me to the right direction of what to do next.

P. S. It seems it's against the rules to ask questions here, but I can't seem to find where else to ask this on xda
English is not my native language, so if you see any mistakes in my posts, please note me.