Are you looking new, used, or either?
Describe "Small". If you don't know, "traditional" knives are historically measured in the closed position, not the over-all open length like "modern" knives are. The size is determined by the pattern, not the brand. Since Traditional knives are a pattern, not a proprietary design, any and all patterns could be (and for the most part were) made by all the different brands.
I would
suggest deciding what patterns you are interested in, then buy it in a Rough Rider/Marbles/offshore Queen/Queen City,
to see if you like it, and it meets your needs first, rather than buy a "better" name, for a
lot more money. That way if you
don't like it, you are not out a lot, and don't have to go through the hassel of selling it. If you
do like it, you can always "upgrade" to a made here brand.

(BTW, SMKW and BTI Schrade are both US companies. The knives are contracted for offshore, rather than made here. They do have a lifetime warranty, that they stand behind, too.)
New or Used:
Christy Knife (can do search here for them. They get mentioned every so often, and are well thought of around here). I think they only sell new from their website, though.
Buck 300 series.
NOTE: 37x and 38x knives are made offshore. Current US production is limited to the 301 and 303, since 2017 or 2018, when the 302; 305; and a couple others were dropped.
From 1966 until 1999(?) when Buck brought slipjoint production in-house, were made by either Schrade (with Swendon Key construction) for the first couple years, then Camillus (pinned construction). Both have long pulls on the primary blade.
The 301 (3 blade stockman, and now discontinued 302 (single clip point blade using the same handle as the 301) are a "large" knife at just under 4 inches closed. The Schrade/Camillus made 307 stockman is an "extra large" at 4.25 inch, if memory serves. (might be 4.125 inch.)
The 303 is a "medium" at 3.5 inch. The other 30x are smaller, ranging from ~ 2 7/8 to 3.25 inch.
Case (Many suggest/recommend buying
new production only if you can inspect the knife in person. Apparently their QC can be hit or miss. They will, of course, fix the misses under warranty, if you send it in.)
Moore Maker(?) (may be a distributor selling contract knives)
Bear and Sons.
(Pre 2004 manufacture) Schrade/Old Timer/Uncle Henry, and pre 1988 Imperial. (The Imperial plant burned down in 1988. Production was moved offshore to Ireland. The tang stamp on the 1988 to 2004 Imperials have "Imperial Ireland" Knives made prior to the fire have "Imperial Providence (or "Prov") R.I. USA. On the 1956 to 1988 knives, the "USA" is vertical, on the right.
NOTE: During the 1988 to 2004 period,
some, but not all Schrade knives were made in Sheffield, England, at a Schrade owned plant, and have "IXL" on the bolster or a blade etch, and the tang stamp.
Used Only Imperial-Schrade Family: Hammer Brand (usually shell construction, and automatics (switch blades) post 1933. Note that after Schrade went under in 2004, the new owner of the brands, Taylor Cutlery, did a limited run of a few patterns under the Hammer Brand name. Those knives were pinned construction with real bolsters, and have stainless steel blades, to help differentiate them from the pre-2004 knives.
Post 1933 New York Knife Company (NYKC/Hammer Brand went under in 1933, and was bought by Imperial)
Frontier, IMP CO, Ulster, Ulster-Old Timer. There are several other Schrade family brands that slip my mind at this time.
Pre 2007 Camillus (also a Schrade family brand, but they did not go under until 2007, three years after Imperial-Schrade.
Sub brands include, but are not limited to CAM CO and post 1989(?) 1990(?) WESTERN. Camillus bought Western in the veryblatec1980's or early 1990's. I forget what year.
WESTERN (Boulder, COL. or Colorado on the tang stamp. Western was also owned by Coleman for a few years, starting in the mid 1980's, prior to going to Camillus. I don't know if Western made folding knives during The Coleman years.
Sub Brand was WESTCO.
There were over 100 brands that went under 1930 to 1939, during the Great Depression including:
Russell, Robeson, NYKC/HAMMER BRAND, (original) Tideoute, (Original) Queen/Queen City, (Original Schatt & Morgan
before becoming a Queen Brand
NOTE: Post Depression era Queen/Queen City - Schatt & Morgan went under in 2019. I forget who bought the names and tooling. The Queen and Queen City names were then sold to SMKW, to raise cash for setting up production if the Schatt & Morgan, in Ohio. I don't know if the "New" S&M have hit the market yet. (originally planned for 2000, but got delayed) They ARE producing a old Queen sub brand; WEED KNIFE (Weer Cutlery?) in Ohio. Reviews on BF for the Weed knives are mixed.
Colonial
There are also decent no-name "MADE IN USA" knives out there.
I
think SARGE
may have some US made knives in their lineup.
Good Luck in your search, and Welcome to the Porch

You can also check out the OLD KNIVES and the Old Catalog sticky threads in the Traditional Forum, for additional knives.
BTW, Schrade, Imperial, and Camillus made knives for
lots of different cutlery companies, and private labels, such as Sears, Beillencamp Hardware, ACE Hardware, Woolworths/Grants/Montgomery Wards.
Colonial made the SHARPS brand for Kmart (RIP), back when they had a Sporting Goods department with more than fishing gear and baseball caps.
If you want a GEC (and your budget can handle it) they occasionally show up in the marketplace here. From what I have heard, at prices more reasonable than at the big auction site. (still well out of my budget, however.)