Are TBCs likely to fix this bending?
 

I have attached short video captured using OBS with an Elgato usb capture device on the left and a Tevion USB capture device on the right purchased from Lordsmurf.
I know TBC are required for good capture but, will adding line and frame TBCs fix the shifting shown on the right?
I also noted that while the video on the right shifts around the objects that should be vertical are not curved like in the left video and the video on the right is smoother as well.

Capture setup
VCR JVC HR-S3900U -> S-Video -> RadioShack Powered Splitter -> S-Video -> Elgato USB
__________________________________________________ _____________|-> S-Video -> Tevion USB

-Theogen

Line TBC should nuke the timing wiggle at top of frame. It presents different in both cards, but still present, still bad.

Frame TBC should nuke some whole-frame movements seen.

The Tevion present slightly different person system, never sure why. Adjust internal card proc amp down by about -5 in the VirtualDub settings.

That Elgato is severely overdark to the source, with some excess color bleeding. Appears to also drop frames not shown in the Tevion, though both are dropping (lack of frame TBC).

Here is a new capture with the proc amp settings adjusted.
I tried to adjust the the settings to make the two capture cards look the same.

Try getting a Panasonic DMR-ES15 or ES-10. It may likely resolve your issue. It's not an true TBC, but it helped solved my issue with the flagging problem on my older tapes.