If it's the newer style door with the rounded frame corners, then it is an industry standard door used by many, many TT and 5'er manufacturers.
Any good RV dealer can get you the replacement glass and it should be an easy DIY job. You might also be able to get one online - there are a number of good internet shopping sites for RV parts. But your local RV dealer might just have the right window glass in stock, too.
But... If I found one of my door windows broken, I'd check into replacing it with clear glass for which I could then make up some kind of privacy curtain. In our 2453, there is no window from the bedroom out on the door side of the TT and I'd like one there. Any good glass shop should be able to provide a piece of the appropriate glass for the application. I'd just pull the whole window frame assembly from the door and take it with me to the glass shop.
I guess that also suggests that you may well be able to purchase replacement frosted or pebbled glass at any local glass shop. And it might well be less expensive than the RV sources.
'12 F250 4x4 Super Duty PowerStroke 6.7 diesel
2011 to present: '11 Cougar 326MKS
1999 to 2011: '99 Sunline T-2453
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