wonder how they got laser printer toner back then

Well, it does appear to have been created on a typewriter. Some of the letters are not completely struck, which is a typewriter characteristic.
I am sure there will be experts comparing the type face, letter spacing, line spacing, etc. to what models of typewriters were available back then.
I seem to see light pencil markings in some of the blocks. The numbers 2 and 9 are there and a dash or two. Those will be subject to inspection also.
Even the watermark will be analyzed for authenticity for that time period.
By the left edge of the image, it appears that it might be part of a bound book so the sequence numbers might be able to be checked for consistancy.
It appears the File Number 151 was pre-printed on the form while the number, 61 10641 under Department of Health appears to be a stamp. I'd guess the leading 61 is for the year. The rest might be a sequence number that can also be analyzed for consistence.
Again, this will all be moot if this document only confirms that a Dr. saw that he was alive on the date the form is completed, 8/8/61.
If any other information was supplied by non-official sources, it is suspect.