We are with Halifax home insurance and maybe because my workshop is in a basement room of the house rather than the garage it is covered as house contents, I made it very clear what the situation was to them and the previous insurer’s also no problem. Garage is the woodwork shop with the usual limitations.
However I would not get too hung up on new for old as far as machines are concerned, if the worst happens, fire, flood, what you need is sufficient funds to acquire replacements of similar used machines so base you’re valuation on this. In many cases you could not purchase a new machine since they are no longer available.
Small tools — well that’s a different story and we all probably have a very large investment in such tools, not impossible but difficult to value and probably frightening when/if you do !
Just my thoughts
John