2 1/2 Escudos From Portugal: Year Needed

I have a supposed silver 2 1/2 escudos coin having:

I) an obverse with:

a) a ship sailing left, 'republica portuguesa' writing along the perimeter, and a date very difficult to read and

II) a reverse having:

a) a shield with 5 sub shields on it surrounded by some sort of basket config. and

b) a '2' at seven o'clock, a '50' at four o'clock and an '$' sign directly underneath the bottom point of the shield at six o'clock

I have been unable to identify this coin in terms of the approx year and silver content. Please provide these two pieces of info.

My book of World Coins by Krause does not show a 2 1/2 escudo coin having the '$' sign directly at 6 o'clock: only at 6:30 o'clock.

Could this coin be from the 1800s?

When was the first 2 1/2 escudo coin made having the '$' sign at 6 o'clock with a left sailing ship?

Thanks