How to patch a textured ceiling to match the original.?

It sounds like sand paint. The swirly patterns were very popular in the 50's and 60's. you should be able to buy the sand paint you need at your local paint store, or paint department at Lowe's, Home Depot, etc. The salespeople should be able to help you with what brush and painting methods to use.

You need to get you a stippling brush clean all the louse flaking pieces off the ceiling. Mix the drywall compound or mud with pant fairly thin roll it out on ceiling then press your brush straight up then give it a small twist. That should get you fairly close to what you need. Then after it drys good paint the entire ceiling to make it all look uniform.

May be best to check with Home Depot or Lowe's for tools and advice.

Good luck hope it turnes out.

Home improvement centers sell a can of textured ceiling spray( eg. spray tex) available in acoustic, knockdown,etc.that go on like spray paint only textured for $8-10 per can u can probably match up the pattern with a Little practice.

go to the home center and buy a round textyre brush and practice a little before you do it