As for the Abu reel, of course you can modify it by getting a frame with level wind which I think in the end it’s better that you buy a full fledge level wind Abu reel. Much easier and even “cheaper” so to speak.
As for the 7HT, there is no compatible frame for it as far as I know, which means not worth the effort, might as well buy a new level wind reel.
Thanks for your kind advice…I believe it is definitely cheaper to go for a new set of multiplier with levelwind. Using my fingers to guide the lines during retrieval is a hassle and pain in the A*S.