Something I heard of from a reliable scource a few years back is that the favorite wood for lures in Oz is "white beech" scientific name ,"Gmelina fasciculiflora" luckily readily available in Australia. Also luckily we have tons of it here in the Philippines and I dare say most of the other tropical countries around Asia. Yup, I have made a few poppers out of it and it does not seem too bad. It has a specific wheight of about 450lbs per cubic meter as opposed to pine which has a specific wheight of about 400 lbs per cubic meter. Teak, mahogony,etc have specific weights of about 650-750lbs per cubi meter. I think the weights given were for wood dried to 9% moisture content if my memory serves. Its definately tougher than pine and is only slightly heavier.
BTW, I think that a looped wire harness glued into a slot in the poppers body is not very secure, and I am sure that good GT's will rip it out pretty darn quick and make a mess of things. For me at least, I prefer to go for the single strand wire through a hole bored straight through the popper. I use a 400lb stainless which is 1.2mm thick that is readily available here. Its available up to 900lbs but I'd need hydrolics to work the stuff. I barrel twist the eye for the head, pass it through a washer, pass the open end through the head,thread the swivel onto the wire at the belly hole of the popper, then continue on out of the tail. slip on an egg sinker of the desired weight/size, then make an eye about 6-8 mm behind the tail and barrel the wires tag back towards the popper tail to make it taught. Its actually less hassle than a glued in harness. also it can be done after the popper is sealed and painted.
I use a long 1/4" wood bit to drill through the popper-with care this can be done fairly concentricly to the center from both ends. I'm still on spray cans for the finish, so nothing fantastic there, and I finish off with rod builders epoxy of which I normally have plenty around. Whatever the results, it certainly is great fun to tinker around with, and makes you think about how you want it to behave. Its also a good cathartic therapy for off-season blues.
Earl.