Looking For Free / Very Low-cost Sources Of Financial & Registry Data For Unlisted Private & Proprietorship Companies In India — Any Leads?

Hi, I’m researching several unlisted private companies and proprietorships (need: basic financials, ROC filings where available, import/export traces, and contact info). I’ve tried MCA (can view/download docs for a small fee), and aggregators like Tofler / Zauba — those help but can get expensive at scale. I’ve also checked Udyam/MSME lists for proprietorships.