I am familiar with the $1300 Ohlins cartridge kits and we have the tools to work on them. Thanks for the suggestion, but not super relevant to the discussion.
Sorry, you must have missed my first comment......I can tell you when I was changing to Ohlins cartridges I did it without any special tools.
Which was relevant, I was trying to tell you it can be done without fabbing anything, but I guess you missed that. I followed up with a suggestion to not bother, because it seems like you were after simplicity, and I am of the opinion you'll never be able to enjoy that with the OEM Sachs internals.
No spring compressor needed with the Ohlins, 19mm wrench, 14mm wrench, 3mm a few other common tools, and since you already have the specific Ohlins stuff, I don't understand why you'd want to keep the OEM stuff, unless you're racing in a restricted class.
BTW.....you can get those cartridges a lot cheaper (new) if you look around.
AND @blachow has a near new set with 3 spring rates for sale now in the forum classifieds, who knows maybe he's negotiable on price, even though it's a decent price he's priced it.