Check this page on the Remington Society of America for a list of places:
http://remingtonsociety.com/rsa/service
We have SOME original parts for that model, we make others. sales@countrygunsmith.net
I have parts for that model. sales@countrygunsmith.net
Numrich Gun Parts Corporation located in West Hurley, New York has many original parts for the Remington Model 11. They have seven warehouses worth of gun parts in their inventory.
Remington, Brownell's, gun shops, gun shows, want ads, e-gunparts.com
You can contact Remington directly to see if they have any parts supply left for the model 1148,or you can attend gunshows,look on the internet,pawn shops,etc.
Only on the used market. Check on eBay, and in the back pages of gun periodicals like Shotgun News or Gun List. sales@countrygunsmith.net
numrich gun parts
lightly oil any parts that move
You can download an owner's manual for fee at Remington's web site.
Remington, gun shop, e-gunparts.com
Numrich Arms.
Go to the Remington website, www.remington.com . Manuals including parts diagrams are available there. sales@countrygunsmith.net