Read from SQLServer database, Write to sqlite, in Rails

I'm trying to figure out the best way to do this in rails.

Basically, I'm reading from a SQL Server database (Which is populated using vehicle rental software) using the activerecord-sqlserver-adapter gem.

Now what I'd like to do is to add further information to these records in my own sqlite database (or postgres, mysql, whatever). So, say for instance, I'm reading information about a vehicle, I'd then like to add images, documents, etc, to this vehicle in my own database.

I absolutely cannot modify the SQLServer database in any way, I may only read from it.

What would be the best way to achieve this?

I hope this helps explains it a little better, although I'm sure I've not given a great explanation.

Thanks for your time!

Martin