PJ:
Your Brazillian Nylon 66 knock-off suits your requirement to a "T", IMO.
There are a couple other older 22 semi-auto rifles that have been "forgotten", but can be had for way cheap:
Mossberg 151 -- mag tube is in the buttstock, very reliable and accurate, but prices have been climbing because of collector interest. The 151K has a 24" barrel and a conventional sporting stock, and the 151M has a 20" barrel and military-appearing Mannlicher stock. I own both models and they are reliable and accurate.
Stevens / Springfield 87 / Savage 6
High Standard 102 Sport King Carbine
High Standard 1041 Rifle
Sears / JC Higgins 25 (made by HS) -- These are all of a kind, and carry the nicknames "Gill Gun" or "Click-Clack" due to two design features. The "Gill Gun" name refers to vent slots or a "grille" of sorts on the left side of the receiver just behind the chamber, reminiscent of "gills" on a fish. Its purpose is to vent gas and partially burned 22LR lubricant schmutz. These guns are also called "Click-Clacks" due to the lockwork design -- pull the trigger and the rifle fires, the bolt is driven back, and if you hold the trigger back, the bolt stays to the rear until the trigger is released. At that time, the bolt travels forward under recoil spring force, strips a new round from the feed block and pushes it into the chamber. The sound the action makes is descriptive -- "click-clack", and your trigger finger has control over the time betw. the "click" and the "clack."
But sounds do not a successful 22 rifle make. I have a Springfield 87, a Sears 25, and two High Standards and all of them have been remarkably reliable and accurate as well. The most I paid was $160 for the Sears 25, and it is virtually as-new with a Japanese-made Bushnell scope from the 70s. I gave $110 for the HS 102 Sport King Carbine, and $85 for the Springfield 87. The High Standards have a really cool feature -- the cartridge loading port in the underbarrel tube is on the side of the mag instead of at the bottom. This was a patented feature that allows the shooter to load rounds by placing them in the gap between the barrel and the mag tube with the rifle tilted butt-down. The rounds slide down the barrel and mag tube and disappear into the feed port slick as mucous on door security hardware.
Accuracy is more than acceptable. I've only papered the High/Standard Sears 25 and the Springfield 87 and I get dime-sized ORH accuracy at 25 yds off the bench. Busting claybirds on edge at 100 yds is boring -- 9/10 or 10/10. Shotgun hulls at 25-35 yds? No problem. And using either Mini-Mags or Wildcats, they are all 100% functional.
Sears 25:
High Standard 102A Sport King Carbine:
Remington 552 Speedmaster -- I bought an older, used 552 some months ago and it's been equally fun. There's some finish wear on the anodized alloy receiver, dents in the stock and forend, and a little rust freckle here and there on the barrel, but for $175 OTD I cannot throw any rocks. Internally, the 552 was the FILTHIEST used rifle I've ever purchased. I scraped a little mountain of debris from that action, and what I could scrape together formed a pile about 1.25" in diameter and nearly 3/8" high. What's amazing about this 552 is that I fired 100 rds of Mini-Mags from the rifle before I bought it, filth and all, and there were no hiccups whatsoever. The bolt was actually "sticky" if moved by hand, yet when cleaned and very sparingly lubricated the bolt slides as if on ball bearings. Dirty or clean, the 552 Speedmaster is another amazing 100%-functional semi-auto 22LR rifle.
BUT WAIT, THERE'S MORE! -- The 552 Speedmaster will feed and function reliably with 22 Shorts, the "High Speed" kind. It won't function reliably with CB Shorts, but mine will feed most if not all of a magazine of std vel 22 Shorts without a blip, or maybe one FTF/FTE per magfull. If shooting HS 22 Shorts, it's like shooting regular 22LR cartridges, only more of them per mag.
SUMMARY -- Noah sez there's no need to invest the $$$ into a new 22 semi-auto or yet another 10/22. IMO and experience, there's a GOLD MINE of older, used, and near-forgotten great 22 semi-autos out there to be rediscovered, and for not much $$$. There's plenty of aged, time-proven "gems in the rough" to be rediscovered at shops, shows, and on the auction sites for less than $200, and in many cases WAY less. Some of these older designs may have played a part in your own childhood, like they did mine. Prices are higher everywhere these days on anything to do with firearms, but the local dealers here are all lamenting the end of the Obama-inspired feeding frenzy of 2009, and they are willing to move on prices a bit.
Noah