Señor Carango, I suggest that you don’t think so much in terms of heavy vs. lightweight gear. Think more in term of efficiency. In other words you should want a rig that you can set up and tear down quickly. Forget about laptops, vocal processor units, extra pedals and other stuff that you have to plug in. I think an important part of these types of gigs besides playing/singing great old tunes is to somehow be socially engaged with your audience. That’s hard to do when you’re busy setting up/tearing down. Try to keep that to a minimum. If I had your gear (and I wish I did!) this is what I’d bring:

Roland BK 5. The mp3 player will be GREAT when you’re setting up. I try to get to my gigs early. The thing is once the old folks see me come in they all start heading for the rec room. It sure would be nice to have some nice background music on while they are waiting around.

Roland BA 330. Just plug your keyboard and your mic and your ready to go. No need for a mixer or vocal processor. It already has good reverb. What else do you need?
Keyboard stand with a attached mic stand (something like Uncle Dave uses)

There you have it- a keyboard, speaker, KB stand with a mic stand, a mic, a mic cable, and KB cable. Hopefully you don’t have to read charts like me but if you do the BK5 has a music rest which you can put your book or ipad on.
Keep it simple and welcome back to the senior circuit.