I admit I was too harsh back then but even the mod's author agreed that it's not the best mod. Doesn't mean that I don't like the mod either, I used it a lot back in the day and it was very fun despite having completely unfitting Jbeam.
If you mean add back the moonhawk sounds Ill add them back in a few hours EDIT: turns out it isnt possible because of the jbeam age
If a mod is as extremely outdated as this (last updated 6 years ago), it's not so easy anymore, it was before several complete revamps of the engine sound system
You cant add the soundconfig section in the jbeam due to the mods age (like Agent_Y said), all the engines would need redoing from scratch and other jbeam files would need revamping for the new fuel, oil, etc slots.