NAV Loan For Sponsor Equity Stake

We have a $2-4mm equity capital need for significant M&A add-on opportunities within an existing portfolio company. I would like to backstop that equity raise to feel confident pursuing all of the accounting / legal costs to execute that M&A, but do not have the $2mm+ of liquid funds at the moment. We own a separate unlevered business that is worth ~$50mm, and have an internal equity stake that is worth ~$10mm... alongside sponsor fees, other income, and ~$3mm+ of other more easily underwriteable, traditional asset collateral that is personally owned (but ineligible for security asset lending or real estate lending). Are there any groups, credit funds, or banks out there that might be a logical fit for a NAV loan against an individual asset with some incremental asset support? May consider a PG depending on the structure and cost of capital. Any recommendations would be appreciated.