I bought a little screen repair kit from a outdoor gear store to fix a tent screen years ago. It is a sort of stick on deal... worked well and is still there. Try googling tent screen repair, something will show up.
'95 SMB E350 Quigley 7.3 https://www.taylorarts.com
... If you have to ask, you'll never understand...
"... torpedo'd, because we don't generally cotton to bullshit around here." -jage
"... do they ooch apart in the night?" -Dia
Google Coghlan screen patch kit .have used them on several tents and one of the trailers that Mamma Bear and Baby Bear paid a visit to in Yellowstone . Not perfect but it lasts and keeps the Bugs out .
stanw99 ... I tried that and it did pull the tear together. I then coated the seam with some silicone glue, so it looks a little gummy. What gets me, is that, as I see it, there is apparent no way to replace the screen short of taking the entire canvas unit off the van. It's really just a cosmetic issue at this time.