Singer 17-41 / fixing it up with a donor 17-16

[Webicons]

First I want to thank everyone who has helped me out with my first trip down the sewing machine rabbit hole. 
I had purchased a 17-41 in rough shape and I’m using a 17-16 as a donor unit to fix it up. 

Can someone tell me how to remove the tensioner “sleeve” from the cover (see pic). Was it originally heat pressed? Doesn’t want to budge. 
 

 

Thanks! 

[Constabulary]

That is not a sleeve the face plate is one piece of cast iron. When you have all pieces of the tension unit incl the spring rest then I think the cracked piece is not really an issue.

 

 

the above pic comes from this thread:

https://leatherworker.net/forum/topic/109757-move-along-and-save-or-maybe-take-a-risk/

EDIT:

noticed it is a picture from your thread anyway

 

Edited September 21, 2023 by Constabulary

[Webicons]

Thank you. I appreciate the insight.  It looked like someone has tried to take it off and mangled it in the process.  
I’m trying to figure out the tension to fix the backside stitches.  Top looks beautiful but the bottom not so much.  According to the manual the needle tension is too loose but as I tighten it the sewing action gets tough.  
Can you recommend some things I should look at?