if you can find a range of straws, coffee stirrers, or other hollow round things you could slip them over the peg to see is you can find a size match. then you could do the same thing sticking solid round pieces into the hollow match and get real close to your peg size.
carry that to the hardware store or dig around to find something.
i was just thinking i would probably drill out where the pegs are and insert some black coated wire. i know most people wouldn't drill out 30 yr old toys though. what about making sleeves to attach solid wire? it would be like a coupling .
something like this, but at a much smaller size. it could be made from rubber, metal, plastic, or anything that slips over the peg.
this is the last heatshrink set i bought.
https://www.amazon.com/gp/product/B07QM ... JMLY&psc=1
it won't work on it's own as hoses though because it won't bend and hold the shape well. so something inside would be needed. i'm thinking coiled wire like inside an old radiator hose might work.
i don't have a devilfish or i'd try and make a hose. if you have an "old cord" drawer or bin somewhere i bet an old charger has a good size wire cord.