robertrs,
A friend of mine thought about Onken cabinets for his Great Plains 604 drivers, but, the Hiraga design and others recommended for this driver are enormous and extremely heavy; he went for a more conventional bass reflex cabinet.
I personally like Onken cabinets; my speaker has twin 12" woofers in an Onken cabinet. I got my Western Electric 713b midrange compression drivers from Japan (most of the best vintage American gear is now located in Japan, Korea or Vietnam). I am a big fan of the same kind of gear prized by the Japanese and I particularly like their old school speakers inspired by US brands, such as the compression drivers and horns that use to be made by Yoshimura Laboratories; they are consistently terrific sounding even though they are made in a crazy array of sizes and configurations. The current manufacturer G.I.P. Laboratories still turn out terrific Western Electric clones, but the prices are unfortunately crazy high.
I have also liked Japanese electronics from Kondo, Shindo and Zanden. Many years ago, I bought a pair of Stax Omega II 007 electrostatic headphones (still own and use them with the Amercian-made Blue Hawaii SE headphone amp). When I took them home, they just did not sound as good as when I heard them at the dealer. When I asked the deal why that was the case, he pointed out that I auditioned the headphones through a Kondo M 10 linestage and I could never realistically achieve the sound I heard with anything less.