Best approach for extracting metadata from scanned engineering drawings?

I have a large number of engineering drawings for different power plants, many of which are scanned PDFs. I need to extract metadata from the title blocks into structured data. I've tried traditional OCR and a few LLM/VLM approaches, but accuracy isn't consistent enough, especially with older scans, rotated drawings, small text, and different title-block layouts. Has anyone worked on something similar? What approach/models would you recommend for highly accurate extraction at scale? submitted by /u/Initial_Mistake9368 [link] [comments]