What do you do when you can't find comprables for a DCF or a prcedent transaction?

I need some help. The private equity firm I work at (think lower-middle market firm) is planning on acquiring a professional services firm (B2B - I prefer not to disclose industry for legal reasons). The issue is the industry is miniscule and there haven't been many transactions in this industry nor information/research regarding the industry.

My MD is hammering to finish a few valuation models and give him price ranges for the firm. I have used CapIQ, Hoovers, Pitchbook, and bloomberg already. I don't have access to other databases.

Any public comp. or transaction I find is either missing a transaction value or key financials (EBITDA, Rev., Net Profit let alone anything else) thus it is hard for me to estimate what gross., G&A, etc. are and reverse engineer the numbers. The data I have found is too widely dispersed skewing the valuation range and my MD won't let me use other companies/industries as proxies.

The team at my firm is small and the other employees are busy on other projects thus I'm slowly dying over here. I keep updating my MD and explaining the situation, he just says try your best and this needs to be done asap.

Any advice is appreciated.