Help to identify what is needed to attached to 1960s era P-Trap setup

[Miamipoker]

I'm a contractor (not a plumber) but I just replaced my vanity in my condo that was built in the 60s. the pipe coming from the wall doesn't look like anything I'm familiar with.. Some type of steel maybe? There is a straight pipe coming from the wall then a 90 elbow.. the end of the 90 it has a few male threads and there is also a nut that screws onto that. Everything looks to be 1 1/2" . The original P-trap got tossed in the trash before I could really tell anything about it.
I'm assuming I need to get straight p-trap pipe to go up into that 90 and then the slip nut tighten around it? What type of material should I use? PVC? Metal? Pictures attached.
Thanks
MP

 

[House Doc]

Are there threads between the 90 and the straight pipe? (Can the 90 be unscrewed from the pipe?) Post a pic of the side of the 90 where it attaches to pipe. Is it an iron pipe, or "tubular"?

 

[bbp]

you need an 1 1/2" captive nut p-trap,chrome plated brass.

 

[Dan the Plumber]

Unscrew the chrome 90 from the 1 1/2" pipe and just install a new p-trap. Plastic preferred. Although you might want to get a new metal slip joint nut and seal like the one in your pic.

 

[breplum]

Another way to go is to use a no-hub type coupling adapter;
One that goes from 1-1/2" pipe to 1-1/2 "tubular".
Cut off the elbow as appropriate with your new plastic tublar p-trap as a measuring guide.