We did not rematt our VWL litho, but what we did was probably much more cost effective (for our needs anyway).
I was shopping one day and saw a picture with a most beautiful frame and perfect color matting. I pulled out my measurements and tape measure, perfect fit! I bought the framed/matted print and removed their print and put in our litho.
The only snafu was the embarrasment that I suffered during the purchase. The print I bought was that famous 'Dogs Playing Poker' print, and I didn't even try to explain to the cashier why I was buying this tacky print.
It cost about $25 total and the frame and matting separatly would have been a bit more than that.
Edited because I didn't catch the last part of your question! Sorry.
I received 4 matted prints from family. To have a custom frame made would have been big bucks. What I ended up doing was cutting the matt to fit the frame. Worked out fine.