I measured the front grip strap and it was approx 2.25".
There is a date code/proof mark by the left trigger guard. This shows the year made. It is a Letter and a Number (except early models where it's just a letter). Here is a link for the conversion:
http://www.9mmlargo.com/year_codes.htm
The Especial was made until the mid 70's. It has 'Especial' stamped on the slide.
The thin extractor came about 1980 and was used until the 90s when they stopped making them.
For spare parts I'd have a few recoil springs (depending on how much you will shoot it. Maybe 1 for every 5000 rounds shot).
I'd also have 2 spare firing pins. These seem to break especially if they are dry fired (a big no-no).
IMO you can never have too many mags. There are some nice aftermarket mags out there that I own and love. I'm not aware
of spare mag springs but if they make new mags, someone has the springs. To date I haven't found a need for new mag springs but I have 10 mags so they don't get used a lot at one time.
Unless you detail strip after every time you use it or you tend to lose parts that's about all you'd need. They are pretty hardy
and a lot of fun. If you like the 1911 design, as I do, you will just love the Llama .22. If you just like shooting .22s then you may not get the satisfaction of a .22 target pistol. Don't fool yourself, it doesn't have a bull barrel and the barrel isn't 6" long. It's for fun and show and is a great conversion piece in the 1911 world.