I know the backplay of these reels are crazy bad (in two spots of the anti-reverse gear), but I don't think you can put an anti-reverse clutch in the sloshs or sealine-x.  I remember there was a posting asking if they could replace the sealine anti-reverse gear with a saltist or saltiga, but I don't think anyone followed up on it.

But these reels are very solid aside from that.  I have both a SL20SH (aluminum frame upgrade) and a SL-X30SHA. 

Possible upgrades: Carbontex drag, beefier handle, Aluminum frames SL20SH (no longer made).

If I can recall, the (white?) Grandwaves come with anti-reverse clutch AND spring loaded anti-reverse dog.

About 15 years ago a very similar unit was being sold here in Canada by the Walker downrigger company they even used the 300 Model name.

Brother, good luck.
I actually think, from a maintenance point of view, the inside screws make sense; but, finding parts for that thing may be rough. Your time might be better spent buying a used 113H.
The Man

No one does better work than John. That tuna looks like it was woven into the graphite.
Very impressive, I hope you enjoy it. Tell her she done good!
The Man

Smooth hound shark? I grew up calling those spoon tails.
Way to go!
The Man

Nice rod, I can't believe you twisted it.   

That is a beautiful combo!  Did you hydro the reel or did it come with that pattern on it, they both look awesome and together really set each other off nicely! - john

David that is an awesome combo, a true bluefin slayer! Hopefully you get an opportunity soon to put the wood to them.

I take really lousy pictures and doesn’t do this rod and reel justice, especially the rod.  I’ll get some better ones.

Good report and a good variety of fish.  Those shrimp flies lol pretty fishy...did you tie your own?  Bill