Wow. That helps a lot. 
Model No. 20 is closest.
This rifle doesn’t have a barrel mounted rear sight nor does it have the extra trigger guard loop.

It’s closer to a 20 than a 25.

High or low serial number?
No forearm indicates early run models

25 with the checkering sanded off

More than one expert has declared that it’s often hardest to find an antique gun, especially a better model, that exactly matches the catalog description.  In the case of the Wurfflein rifle under discussion, I'd say that's the case.  Nor is that surprising, for William Wurfflein, like most top-grade gunsmiths even today, was more than willing to build to a customer’s specifications.

First off, please note that I’m hampered by the gun having at some point been very improperly “cleaned”.  Still, my best guess is that except for the shop-designated Off-hand Butt Plate, which looks to be nickel plated as usual, the action, barrel, etc. were blued.  Also, without actually examining the gun personally I won’t assert that there originally was checkering on the stock or the forearm.

In a nutshell, my guess is that this rifle is a No. 25 “Special” Mid Range Target Rifle, base priced at $45, and here given these money-saving customizations  :
     1.  A Beach substituted for a wind gauge front sight;
     2.  A plain fore-end and a butt stock with a little figure substituted for those with “fancy curl”;
     3.  An Off-hand butt plate substituted for a Swiss;
     4.  Checkering of the stock and fore-end omitted.

Other notes:
     1.  As for the “.32" caliber (Wurfflein never seemed to stamp his barrels), a seller’s update says it’s a .32-40 .  That would be nice.  But it might also be a .32-35 (also available for this model) - i.e., a chamber cast will be needed.
     2.  The seller calls the bore “very good”, which, unfortunately, can mean anything from “shootable” to “yes, you can see daylight through it”.
     3.  The seller asserts that the rifle “locks up tight”.  Since it seems to have suffered from poor storage and poor maintenance rather than use, I’ll tentatively accept that.
     4.  The vernier tang sight is a very nice extra, worth an easy $300-$400 by itself.

Finally, the seller's starting bid is $1500, so I assume $1650 is his unadvertised “Buy-It-Now” price.  To my mind, that’s a maximum "from pictures" valuation, but not an outrageous one.

Bill Lawrence

Howdy, I know I haven’t posted here much, but I do read a lot and thank you all for your great info and insight!  I know too that I am late coming into this thread, but last fall I acquired a Wurfflein No. 2 Sporting and Gallery Rifle myself and have become fascinated with all things 'Wurfflein'.  (I also owned two modern Knight KP1 Wurfflein rifles and 4 barrels prior to finding my No. 2.)  I have been perusing the internet for a couple of months now collecting/saving every photo I could of every original Wirfflein cartridge/shotgun arm I could find, and whatever Wurfflein literature was to be gleaned as well.  While I am certainly no expert of Wurffleins, I do agree with some points made by MrTipUp, but do tend to have my own perspective sometimes.

I have done stock refinishing, recheckering, new checkering for well over 30 years now and handled many stocks refinished by others.  After looking very closely at the photos posted on GB, I can see no evidence that there was ever any checkering to begin with to sand off.  I only see originally uncheckered, but perhaps stripped, lightly sanded and refinished, wood that has shrunk back a little over time.

As far as the correct model designation for this rifle, #5284, I would tend to agree with Welldone and westerner, in that it appears to me to be closer to being a Model 20 Mid Range Target Rifle than it does a Model 25 'Special'.  With all due respect to MrTipUp, what would be gained by stripping down a Model 25, given the omissions listed by him, over adding extras to a Model 20?  From my perspective and from the standpoint of frugality, in this case it would seem more logical to me to start low and add on rather than start high and take off, thus ending up with the same end result for a bit less money. 
(To be continued in my next post:)