@Jake Wilson Thanks Jake. Both bases have a number of tables, scores of fields, linked records, lookups, rollups and automation triggers so the thought of building from scratch is anything but appealing! In the absence of finding solutions in various communities my own solution roughly followed this path: 1. Choose the base with the most existing complexity attached to it as the host base. (In this case, it was the one that fired a lot of Make.com automation triggers). 2. Set up the second base to share and sync all it's Tables and Views and Fields. (Hindsight) Pro tip#: Name every View including the default 'Grid View' to match the source Table name so it's more easily identifiable in the new target synch base. Especially if you're synching more than one Table. Pro tip #2: Unhide all the fields and remove filters from the primary View so you can easily see and check everything you need comes across (as filters/sorting do not). 3. Identify the Table with most linked records. This proved helpful as Airtable will automatically prompt you to synch the linked tables and means you don't have to manually synch all the tables. (Otherwise, just synch one Table at a time). 4. After synching tables, if applicable, check all the records reached the target base. (I simply switched on Filled/Unique in the Summary for a quick reference to compare each field's records in the source/target bases). 5. Once you're happy the source base is effectively duplicated in the target base, unlink the 'remove' the synch source (synch settings) and prepare to 'rebuild' the base. (While they are synched you can't make major changes to the target tables and once the synch is removed the field types are all basic. For example, no formulas, lookups or rollups will remain). 6. Rebuild the base #1. This is the step where you have to check the settings of each target field and compare it to the source and make all the appropriate changes; e.g. formulas, lookups, rollups, etc. (In my experience, this was still a painstaking process, (especially making sure you don't make mistakes), but it was definitely easier having completed all the above steps). 7. Rebuild the base #2: This is the step where you'll need to rebuild all the parts you can't synch such as filter/group/sort settings and any automations you may have built. (I can't comment on whether or not you can synch Interfaces or Forms).

Same with Airtable AI. I have been impressed with how useful Omni has been to help me with several base builds, but when I hear what my Notion pals can do, I realize Airtable still has plenty of upside to come.

I fixed it... Single curly brackets for the Airtable field name, no spaces, typed "=" (not Make (green) "=") and typed quote marks around the variable.