So what you didn't say in your original post is that you can not remove the slide because you are unable to dry fire the gun, is that correct?
Just a side note, is the magazine removed from the gun?
If you do have the slide assembly removed from the frame than the YouTube video I posted will...
It is probably cheaper to get the pin via S&W but here are some options.
Smitn and Wesson SD9VE 9mm Trigger Bar Assembly, Slide Stop Lever & Trigger Pin | eBay
Smith & Wesson Sigma SD9VE Trigger Assembly Slide Stop Internal Parts | eBay
Smitn and Wesson SD9VE 9mm Small Parts Lot | eBay...
Do you mean like this?
Here is the SW357V barrel installed in the SD40VE slide.
The barrels look to be the same. The SW357V barrel is on the top, SW40VE center, and the SD40VE barrel is on the bottom.
http://smith-wessonforum.com/attachment.php?attachmentid=266016&stc=1&d=1485033678
I just recently acquired my first SD9VE. I have had SW9VE and other Sigma variants for years. Your question got me thinking so I took these pictures. They appear to be the same. They both fit in the other gun without any issues. I have yet to fire the SW barrel in the SD and vise versa...
Yes, it should. They look to be the same. I have a fitted a SW barrel in a SD and vise versa, but I have not shot either of the guns with that configuration.