One of the immutable laws of the universe taught to me once.......... ............th ere is no such thing as something that can be put together that cannot be taken apart.
Your devotion to the task is the only limit. Now complicated by manufacturers who hate people like me and now glue or mold assemblies together now to stop us from getting into them. In most cases that doesn't even work. I fix $200 door latch assemblies on my Focus cars by grinding off rivets and drilling and tapping for screws, total cost to fix around $5 to me. No way I'm paying for expensive throwaway parts twice that I can repair myself.
Yes, there must be seals and if bad you will be presented with how to change them, luck with that and part of the task if it goes there. You can't be afraid of things if you really want to fix them. I personally have found that I can still reuse them, just like pulling a 20 year old master cylinder apart and rehoning and putting back together to work fine for another 20 (done to my Pinto wagon). The seals will still be good or............ .........they won't. Either you damage them taking apart (your fault, no insult intended) or they were bad already and part then no good till you fix it anyway. Lots of places to find o-rings, the issue becomes getting the proper thickness, size not a problem. You can often squeeze a slightly thicker one in there and it will work fine, sometimes not.
Here's a tip that may save someone a bundle on old parts. Not saying to do this at all on brake parts BUT you CAN clean parts off in petroleum distillates just like every tech or teaching method in the universe says you CANNOT on brake parts. Occasionally there may be a need to go there, I've often found that alcohol or brake fluid doesn't clean parts for squat, they don't cut the old brake fluid. I've used say gasoline, the parts will swell all out of shape and you're firmly convinced you ruined them. Let the parts sit for 2-4 days so the VOC of the fuel can evaporate from the rubber and come back to find the part is normal size and shape and good to go again. But clean now. I have already put my life on the line several times doing this through the years and I assure you the parts are OK and will work well. BTDT. They must of course start off tio begin with as still supple rubber, they cannot be hard or have cracks in them.
So, if you did solvent not knowing, then no need for panic there.
But then, I've recovered new brake pads that one week old blew a caliper seal on and fluid soaked into pads, I reused them to full length of time (years) and they stopped car on a dime.
It behooves one to be a bit cynical of all the things conventional wisdom holds for us, much of it is highly inaccurate.