Lost GC and travelling shortly

[blore40]

All,

I have had a GC for the last 5 years. I reside full time in the USA, save for occassional travel to India for 2-4 weeks. I lost my GC two days ago . I am travelling to India next month. Based on information gathered from this forum and other sites on the internet, I have:

1. e-Filed I-90 and got a receipt number. I cannot yet check for status of this receipt.
2. Taken an appointment with Newark NJ immigration office to talk to some one there regarding travel documents needed for re-entry.

Questions:
1. My receipt starts with MSC (Missouri). How long does Missouri (or NBC) take to process I-90 forms? I could not find this information anywhere for MSC.
2. My passport has the "red" green card stamping when I entered the country after my Consular processing. Is this enough to travel? Should I get a travel document?

Has anyone been in such a similar situation? What corrective steps did you take?

Thanks in advance!