From memory (although a couple of these are sitting on my desk in front of me and are confirmed)
Serenar 50mm f1.9 - 40mm
Canpn 50mm f1.4 - 48mm
Canon 135mm f3.5 chrome 48mm
Canon 135mm f35 black 48mm
Standard sizes for many lensesCanon lenses in this era were 40mm or 48mm. The Canon 50mm f 1.8 in chrome is also 40mm as is the same lens in black. I do not own the 35mm or 28mm so cannot comment except to say that I think (???) that the 28mm may use slip on filters like the early Leicas in perhaps 36mm or maybe 34mm as per the photo of the 100mm f3.5 below, but others will need to confirm this. Many Canon filters have a chrome ring and incidentally look very nice when mounted especially on a chrome lens.
Another option that I exercised is that at one time Canon sold a complete set of black and white color filters which came in a little plastic container (see below). I had one many years ago and sold it. If you can find one they are a good buy.
Canon lenses and accessories are addictive - good luck.
The above photo reminds me that another thing I have seen is that some Canon lens hood were designed to take series filters (series 6) - the filter went into a holder in the hood.