It takes a while to get I-90 receipt from USCIS.

suggest to send I-90 by certified mail. that way you can show local office the receipt of Certtified mail along with a copy of your I-90, 485 approval notice and 2 pieces of photo ID such as driver's license, EAD,AP, etc. to get your I-551 stamp on pp.

As far as I know, one need to report to police dept for GC lost. you need a report from police dept to file I-90 with USCIS.

Just my two cents.