Hello,
After reviewing your design brief, I decided it would be best to take your existing well-known logo and use that for your anniversary logo. I came up with two initial ideas, one that is very similar to your current logo: #6, and one that is a little different and brings in a more modern scroll: #8.
Let me know what you think, and we can go from there. I am excited to work with you on this, as these types of projects are right up my alley :)