I completely agree. I lost my HP 48 during a move and still mourn it. I bought an HP 41C on eBay to comfort me, because I yearned for the 41 I saw advertised in Scientific American as I was growing up. I loved writing programs in https://en.wikipedia.org/wiki/RPL_(programming_language), a Lispy dialect of Forth.
HP still makes RPN financial calculators. I recently switched to using an HP 12C at work, after holding out for a long time. It's amazing how quick it is once you get used to RPN, and I love the solid feel of the hardware. You can pick one up for around $50.
I still don't understand how "algebraic" input won ... it requires so many more keystrokes. Perhaps it makes sense for students in lower grade levels, but once you get proficient, RPN is a no-brainer.
I have a 128kbyte HP 48G in my closet and I will never part with it. It's a fine bit of hardware hackery from ages long, long gone by: four RAM ICs stacked on top of each other and a friend of mine did the wizardry soldering where most of the legs are just kinda ran together like so many tiny waterfalls and the control legs are soldered separately.
Swissmicros makes replicas of the 15 and 41 (among others). I need to get one to replace my 35s (keys starting to break after a couple years) some day.
A long time ago, some demon soul from hell decided to kill them product lines. The world never was the same, afterwards.