Gathering info about HP 41 and HP 42s

[Cancuino]

Hi all,

I actually own a HP 48G+ and a HP 50G but I'm looking for a special calculator. It must be pocket sized and with some "history" on its shoulders, that's why I'm focusing on these two masterpieces.

Since I'm not an expert on neither of them I'm gathering as much info as I can to make the right call, that's why I decided to write this post here. I hope you can teach me many things about them.

The 42 looks like an actual calculator, great size and a lot of included functionalities.

The 41 is like a swiss army knife, you can add a lot of modules so it can do whatever you want. I've also read about the Monte Dalrymple mod. Could you explain me something about this?. It sounds interesting but it is really expensive though.

Thank you all and best regards.