Hi Lee,
Congrats on the purchase, they look like awesome refractors, looking forward to a review. As for a flattener how about
:
http://www.teleskop-express.de/shop/...efractors.html
hang on if you got the SW one you should be ok
http://www.teleskop-express.de/shop/...cts_id=6743#cs
this says it doesn't change the FL
Russ