I don't think there are many transcripts issued by universities in the West that have seals.
You state that your diploma was stolen by a previous employer.I'd have thought that it was more likely to have been lost by that employer,especially if the employer were a Chinese one.
I have a transcript of my degree here in China - I was told by a school waiban at one school that that was preferred to an actual degree certificate by the provincial education authority as proof of someone holding a Bachelor's degree.
That said,I should add that my transcript is stamped by my university and signed by the university secretary,all be it in the form of an initialled scribble.
But the university's watermark can be seen clearly on the transcript if you hold it in front of a strong electric lamp.