Here’s a mid-1930s Sheaffer Balance H74TC, which is a medium-girth, full-length lever-filler in marbled Marine Green with a peaked round-ball clip. While I had it in the shop, I noticed an unusual construction — the cap had a partial liner of another celluloid, which appears to be the same stock as was used for some WASP models:

Since I first spotted this, I’ve kept my eyes open for it, and sure enough, other examples have turned up. This one is a Jade 5-30 flat top with several other unusual attributes; the “5-30” imprint on the top of the cap is double-stamped, and the cap might have started out as a White-Dotted Lifetime cap, but it was demoted, and the dot was filled — but with a later, more stable Jade celluloid: