Whew, spent almost whole day on memory upgrade - now with 64MB RAM.
The chip stacking and soldering part was easy. The fourth level was soldered in about 40 min. I believe the trick is to use the smallest diameter solder wire or not use the solder at all if lower levels contain enough of it to be able to "paint" the upper joint. Even RAS pins were not that bad. For those pins I broke off the lower half of the pin and bent the pin half way up before bending the rest of the pins.
The worst part were the wires. I've got those teflon insulation ones which is a pain to strip. The hardest part with the wires was to solder three 30GA wires to RAS1,2,3 pins on the CPU.

Thanks to Paul for making the memory chips available.
Now I can do native compilation on the unit

The obligatory photo is included.