I've taken a look at A 283 and A 285 and yes, the chemical composition of your old steel fits into A 283 Gr B and A 285 Gr B.

A 283 Gr B.
Carbon 0.17% max, Manganese 0.90% max, Phosphorus 0.04% max, Sulphur 0.05%max, Silicon 0.40% max.
A 285 Gr B.
Carbon 0.17% max, Manganese 0.98% max. Phosphorus, sulphur and silicon are not stated.

Therefore, I stick to what I've said on my previous posting: figure out your WPS as being an A 992 steel to a low carbon one.
Now, take a look at what Al (803056) said on his posting that you can find following the link Lawrence has below: steels from the 30's were riveted or bolted, not welded, so the main concern was their mechanical strength, not chemical composition. Therefore, the composition of one heat could be quite different from the composition of the following heat. There's little doubt (no doubt at all, I'd say) that the structural members used in a building belonged to different heats, so that one beam is easy to make a weld on but the adjacent column is difficult to make a weld. Read Al's comment and take your own conclusions. 
Giovanni S. Crisi

I have to agree with you Marty!

Back in the early Nineties while working as a field erection supervisor, quite a few of the buildings on Park Avenue were found to have the same type of steel you're talking about, and I also remember vaguely that the steel was made to ASTM A7 as well as it was no longer being an existing standard also. We also welded it to A-36 with no problems as well with an E-7018 H4 electrode as well... I never heard of any problems with those welds afterwards either!!! ;)

Most of the structural rehabilitation work was performed on the mid to upper floors of these multiple story buildings and most of the problems were found to be towards the columns around the corners of the buildings due to erosion of the brickwork cement joints which caused water to corrode the structural steel in an accelerated manner... These buildings were also built in the late nineteen twenties - early thirties and we worked on 5 or 6 of them if I remember correctly.

I also remember that they were considered luxury hi-rises back then, and the tenants/apartment owners who had to be temporarily displaced because of the required work, were sent on 2-3 month cruises on those huge luxury ships of the line with first class accomodations which were a pretty good deal considering that they had to stay away from their residences until all of the work was completed!!! ;) Lots of tricky "Iron work" was performed in order to rehabilitate those buildings and they're doing really well today ever since according to an operating engineer friend I have in New York city who psses by there on a daily basis during his travels throughout the city going to and from job assignments.

Draftingman! Once again, "Weldcome" to the World's Greatest Welding Forum!!! Now I don't know what your set up is like and I'm not going to speculate either but, do you have structural engineer working with you that is familiar with the older buildings in NYC??? Because if you don't, it may be a good idea to consult with one that is, because their knowledge is unique with the older buildings in the City, and there are many that are not hard to get in touch with, because most of their knowledge has been passed on to the newer generation of some of the structural engineers who reside on most of the current projects going on in the Big Apple believe it or not!

And the Dept of Buildings inspection department still do have access to a bunch of many of the original plan drawings with some details on the steels used in the general notes or the bill of materials as well, and some even have the original contract documents with all of the necessary information, but you're going to have to assign someone there for probably a day or two, spend no more than $100.00 to retrieve all of the necessary information for the building you're working on whether it be a Federal building or not, so you might want to consider that route also, if you do find yourself having a hard time tracking down a structural engineer familiar with the older buildings in the city.

Respectfully,
Henry 

I am Lord Voldemort.

+66 6666-666 is my direct line.

Mr. Andersen,
The link you have put on your message leads to a gold mine. Imagine: none less than the New York State Steel Construction Manual, for free!. Thankyou very much, Sir, you have rendered a wonderful service to us engineers frequentors of this site.
I'm a Professor at Mackenzie Presbyterian University in Sao Paulo, Brazil, and will recommend the professor of Structural Steel Calculations to download the Manual.
Giovanni S. Crisi
Sao Paulo - Brazil
P.S. 1. Don't bother to Inspector 3.2's jokes, he has a particular sense of humor and likes to tell jokes all the time on his postings, but he is a harmless good guy. Everybody of us like him.
P.S. 2. Henry, you also have posted golden links on your postings, for example those leading to Sarcos's Manuals on the Metallurgy section of this Forum.

Note that the 250F in the NY SCM is sort of a default preheat for field welding if your steel is not listed in their preheat table.  You'd still need to take steps to verify that your historic steel is indeed considered weldable.

Hg