Mr. PC
The first thing I need to do is correct a misconception, I
don't "have a good many Hollenbecks". I own three and two of those are the rarer side x sides as those are my primary interest. I became interested in Hollenbeck double guns because of my interest in Frank Hollenbeck and the Syracuse Arms
Company. Mr. Hollenbeck designed The Hollenbeck/Syracuse Arms gun, the Baltimore Arms gun, and the Hollenbeck Gun Company gun; so I've studied all three designs because of his association with each and thus own representative examples.

"I've only handled 4 of them (two of which I now own), and every single one has had action issues of some sort or another. The most glaring being that the rifle barrel safety usually doesn't work (if it's even supposed to, more on that later), nor the disconnector whatever-it-is on the front trigger (assuming there is one; more on that later also). Even this parts gun where all of that *does* (supposedly) actually work has issues with the break open lever not staying to the right when the action is opened."

Although I've seen and handled several Hollenbeck drillings, I only own the O Grade drilling referenced above; and since it had mechanical issues when received, it's the also the only example I've ever disassembled (which does not qualify me as an expert!). Now I could be wrong, but there is no safety for the rifle barrel. As to the "disconnector" I'm at a loss, but the rifle barrel is simple to operate; one simply pushes the lever ahead of the trigger guard to cock the hammer, then pulls the safety slide rearward and she's ready to fire. According to a Hollenbeck catalog, the rifle hammer "can be let down the same as any hammer gun". To be honest I've only dry-fired mine since Buck worked his magic but to un-cock the rifle barrel I make sure the safety slide is all the way to the rear (or on safe), hold the rifle cocking lever with my left thumb, then pull the front trigger to release spring tension. At that point, and using my thumb for control, I simply allow the cocking lever to slowly move back to the un-cocked position. As to the opening lever, I suspect you have a weak top lever spring.

"Have yours been as problematic? I wonder if the small parts aren't properly hardened or something."

Don't have the experience to speak to that question; but can tell you there are at least several minor parts differences between the early Three Barrel Gun Co models and the later Royal Gun Co marked models.

"Additionally, how is the front trigger on these things supposed to work?"

Unless the rifle barrel is cocked, the front and rear triggers work exactly like double triggers would function on any other double gun, as does the automatic safety slide. Again, to fire the rifle barrel cock the rifle barrel hammer by pushing the thumb piece all the way forward; then pull the safety slide all the way to the rear (which would be the "safe" position if shooting the shotgun barrels). The rifle barrel will then shoot when the front trigger is pulled.

"On my 12/.30-30, the safety has no effect on the rifle."

That's true, the rifle function was never designed with a safety as we find on standard double guns. All Cherry's ads for these Hollenbeck drillings state that the rifle barrel safety doesn't work. Obviously whoever drafted that ad knew squat about Hollenbeck drillings; Hollenbeck never intended the rifle barrel have a safety.

"To fire the rifle, you leave the safety on, cock the under-lever, and pull the front trigger. Or hold the lever, pull the trigger, and gently de-cock it to safe it. If the front trigger is squeezed while the safety is off and the rifle lever is cocked, the rifle hammer falls, then after a bit more pull-though so does the shotgun."

That's exactly the way the gun is designed.

"On this 12/.32-40, the safety prevents the rifle from firing when it is cocked. However, if you take the safety off and squeeze the trigger, both the rifle and the shotgun fire *at the same time*, which is not desirable."

Clearly a monkey has been hacking on the mechanism of this gun so who knows what may have been damaged or screwed up? As FYI I had Buck remove the safety slide from my O Grade as I prefer a manual safety (I did save the part however).

"Perhaps *this* gun has the problem and my .30-30 is fine. I had assumed that there was some kind of disconnector arrangement inside there that locked the shotgun striker back while the rifle was cocked, requiring a trigger release to reset after the rifle had been fired, and that the safety was supposed to safe everything, even the rifle."

Your 30/30 is working correctly

"But I haven't had either of them apart to take a gander yet. How do yours work?"

I took mine apart in order to see how similar the shotgun action was to the Syracuse and Baltimore guns, but I have little ability to perform repairs. Assuming you wish to salvage this gun my advice would be to send it to a gun mechanic as I did with mine to Buck Hamlin. As to the loose rib, some gunsmiths won't relay ribs on drillings as it is very difficult to properly align the rifle barrel. If you choose to salvage this gun you may wish to purchase a reprint of the early Hollenbeck catalog listed for sale on Gunbroker (Item #817337341) as it contains several diagrams of the Hollenbeck mechanism.