Ideally youd use a shottky, but the voltages are too high. id get something categorized as an ultrafast diode. stth1r06 is my favorite.
https://www.digikey.com/product-deta...43-1-ND/654613
the biggest thing to tweak will be C2. i would think values between .01 and .1uf are reasonable. i thought .022 was a good place to start.
if the brigtness ends up on one end of the dial instead of centered, you can adjust one of the 470ks to tweak thr bias.
if it looks okay, and still synchs etc, youre good to go. if it interferes with synch..try to increase r5 to about 1k.
you could use WW on thr 470ks, but i wouldnt use them in the video path.
no guarantee this will work, but its cheap, and it looks good on paper.