Can old 78's be played on a Victrola?

That's what they were meant to be played on. You could use a cactus needle.

The answer to your question is yes. However if you value your 78s this would not be a smart thing to do. I would suggest buying a seperate cartridge to use while playing 78s on a "standard turntable".

So all 78's and/or any old Victola albums are best NOT played on a Victrola??

It would be better to play them on a turntable that does 78 RPM and has a 78 stylus. You can get a Shure cartridge and get an interchangeable stylus for 78 and 33,45rpm.

I agree with getting a cartridge that has a stylus for 78s.
The Ortofon OM series has a 78 stylus available.

78's sound magical on a victrola. my friends who listen on 78 cartridges are always dumbfounded how much more presence and "soul" comes thru on my victrola. I guess it might be a little like an old violin, there is something special that the aged wood imparts. For example, I've never really enjoyed Frank Sinatra, until I heard him on 78's on a victrola, it's just a different experience. Heifetz also has never sounded better, and I think it is the most accurate portrayal/presentation of his playing/tone. All of that supposed coldness is nowhere in evidence on most of his 78's when I listen on the victrola. as a matter of fact he comes across as very warm and human.