I did more web searching & struck gold. I found some excellent photos & great information about the Southampton’s smoke system (the Southampton is identical to the Richardson except paint & markings).
Smoke fluid goes in the little tube on component “B”, not “A”. When the deckhouse floor is installed that little tube fits snugly into a raised ring on the inside surface of the deckhouse floor. The rubber plug goes through a hole in the deckhouse floor (see photos) to seal up the filler tube.
I’m going to rework the filler tube arrangement by enlarging the hole in the floor so it’ll fit around an extension tube that I’ll add onto the existing filler tube. I’ll seal the extended filler tube with a snug-fitting vinyl cap (I have dozens of vinyl caps on hand). Doing this modification will make it a lot easier for my clumsy fumble-fingers when smoke fluid needs to be added.
I emailed Hobby Engine today via their website’s “contact us” page & asked them for information about the smoke system. I’m also going to contact Nick at Harbor Models tomorrow & ask him for advice as you suggested. I’ll be sure to “tell him Ed sent me”!
By the way, have you had any contact with Doug (RNinMunich) lately? I half expected him to offer up some advice about this topic. A couple of weeks ago I replied to something he posted on the “LED Mast Lights” topic, but he didn’t respond. I also sent him a PM to ask how he’s doing, but he didn’t respond. He used to reply pretty much right away whenever I asked him a question or for advice. I hope he’s all right & I also hope I didn’t say something that insulted him in some way. He did a lot of design work for my tug’s lighting upgrade project. That upgrade is definitely going to get done; it’s been held up all along by a string of eye infections, then my fall, surgery & recovery. If you hear from him please say “hello” for me.
I’ll post back later on & share whatever information I receive about the smoke system or fluid from either Hobby Engine or Nick at Harbor Models.
Thanks for your input & advice, Ed. I appreciate it!