Wow $575 for a used 36 with no box, papers or tools? That is so high I would not even attempt an offer. The seller obviously thinks his gun is more valuable than it is.
For reference, I got a 90+% M. 36 with all the tools still sealed in plastic, the original box and all paperwork. It was list priced at $349.
In general, the older a used gun you can find, back until the 1950's or so, the more craftsmanship and better materials went into it.
I would hold out for a more affordable Model 36, or if you want a new gun Bud's has great deals on these...
Smith & Wesson 642 .38 Spl+P $361.00 SHIPS FREE
Smith & Wesson 637 .38 Spl+P 1-7/8" $367.00 SHIPS FREE