04-05-2017, 07:58 AM
As far as I know, there are no straight filament bulbs available. Each manufacturer had their own variation in filament design. Some early production NOS GE bulbs have a reasonably straight filament and I select the best one from those.
http://i.ebayimg.com/images/g/W7kAAOSwUE...-l1600.jpg
http://i.ebayimg.com/images/g/W7kAAOSwUE...-l1600.jpg