2 ½ Öre Sweden, any information on it?

I was visiting the Pohjanmaa museum at Vaasa/Vasa when I saw a coin I have never seen before, a 2 ½ Öre coin. The collection on display with coins from Sweden, Finland, the Russian Empire and Georgia had belonged to Mauritz Hallberg (1851-1924). I do not own any catalogs so I don't have a lot of information on the coins not on Numista.
I'd appreciate it a lot if someone could tell me about this coin, because it currently isn't on numista.

https://www.ngccoin.com/price-guide/world/sweden-2-1-2-%c3%b6re-km-235-1661-cuid-1099395-duid-1550444

On the other side is 1661 date.
Sweden 2-1/2 Öre KM# 235
Composition: Copper
Weight: 44.3000g
Obverse: C. R. S. above crowned shield
Reverse: Value above three crowns

Yes, a search on here (KM# 235) has no results >
https://en.numista.com/catalogue/index.php?mode=avance&p=1&l=&r=Frankfurt+FREIE+STADT&e=sweden_section&d=&ru=&i=&ca=3&no=235&m=&v=&t=&a=&w=&dg=&f=&u=&g=&c=&tb=y&tc=y&tn=y&tp=y&tt=y&te=y&cat=y

Also there are only three 1661 Sweden coins om here >
https://en.numista.com/catalogue/index.php?mode=simplifie&p=1&l=sweden_section&r=1661&e=sweden_section&d=&ru=&i=&ca=3&no=&m=&v=&t=&a=&w=&dg=&f=&u=&g=&c=&tb=y&tc=y&tn=y&tp=y&tt=y&te=y&cat=y

I will create a basic page for it now, and maybe add more details or pictures later.

This 1661 is the only 2½ ore in Krause. Look at the values and you know why it's not a surprise you've never seen that coin before.

Here is the page I created - will add more to it >
https://en.numista.com/catalogue/pieces173629.html

I'm quite suprised how many precious coins are in the collection of Hallberg. There are lots of coins worth a lot, including patterns, platinum roubles and many ducats.

Very scarce coin. The diameters vary a little. NGC prices are a bit off, it's around 1500-2000 in VF, though it's not often they become available.

Very impressive museum collection too for a small place. The platinum 6 roubles is super rare and the swedish 8/6 marks look in insanely nice condition. May have to visit!

These pictures can be used as of approved source https://www.acsearch.info/search.html?term=1661+öre&category=1-2&en=1&de=1&fr=1&it=1&es=1&ot=1&images=1&thesaurus=1&order=0&currency=usd&company=

There are also a few plate dalers (three worth 2 dalers and one 1 daler) from the mid-1600s, which I haven't seen on numista.

Wow! That's a very impressive collection. I suppose that the platinum roubles and ducats showcased here are very scarce.