ISO 12100 is the A-type standard for machinery safety.

ISO 14120 is the B-type standard for machinery guarding.

Remember if you design, manufacture and fit guarding yourself in house then it is still required to be CE marked indepenently of the machine it is fitted to because it is safety equipment being placed on the market/into use on its own as it were.

Then for interlocks for the guarding you would be looking at ISO 14119 for selection, then EN 60204-1 for the design of the electrical circuits for the interlocks and ISO 13849-1 for the design of the reliability of the interlock system to give it an adequate performance level to protect the user adequately and be realiable, then ISO 13849-2 to validate this design. If you are using programmable electronic systems to "manage" your interlocks such as a PLC then it must be a safety PLC, then the software will need validation to EN 60261, unless it uses pre approved and pre validated function blocks.

Then you could use the C-type standard for the machine type you have to assess the recommended guarding for the hazards.

Then you will need a technical file for the design of your guards, this will need to include design calculations to prove the strength of the guarding to contain any forseable ejections from the equipment in the event of normal or forseable abnormal operation.

Strictly speaking it doesn't matter if the guarding is required under PUWER or the SMSR as the requirement for the manufacture and supply of guarding to new or existing machines falls under SMSR and thus falls within the CE marking requirements.

So it seems these are existing machines.

You still have ISO 12100, ISO 14120 and then with your additional information about gaps and distances be looking at ISO 13857.

Remember though that guarding must be fixed such that it requires a tool to remove, and a coin is not considerd a tool.

Also, guard fasteners must remain with the guard or machine and the guard must if possible not remain in position if the fasteners are not secured.

Then there are still the c-type standards for the machie types which will give you what is expected as current practice.