According to the operations manual I found (on Fluke's website for USA), the memory can supposedly be upgraded from "standard" 8K samples up to 32K samples - the manual on page 4 reads:
"8K sample acquisition memory, expandable to 32K in 2 channel versions" - page 5 reads:
"Memory extension offering 32K acquisition length and the ability to store 156 traces (of 512 samples each) in memory for 2 channel versions" - page 75 (4-30, 4.6) reads:
"If the memory expansion option is installed, the record length can be adjusted between 32K and 512 points"
There are a couple more examples, but you get the idea - according to the manual, there is some kind of "memory extension option" available for the scope. Is it likely that they replace entire thing? It doesn't seem likely to me; at worst, I would think that there is some kind of daughter board with memory on it that is swapped out, or the memory is added to the board, or a second board is added.
I am just wanting the service manual in order to determine what is needed for expanding the memory, without having to open the case (it has an intact factory calibration sticker and tag - I'd like to keep it that way). Having that knowledge would help me determine what I am looking for, and what costs I am looking at to have the memory expanded. It might be out of my budget...