Hi @Craig_Swan
Be prepared for an answer I positively know you won't like.
You can't do it with out-of-the-box Map3D tools. AutoCAD Map3D doesn't have the built-in capability to do that, no matter how or who, desperately tries to justify workflows to the contrary. You'll need 3rd party software to LINK the individual pipes and parts to a 'named' grid cell. I told you you wouldn't like it, right?!
<<Alternatively, you may manually link each individual pipe object to a named CELL in the GRID but that's not an efficient workflow and painfully time consuming.>>
Your sight is in Edinburgh, correct?
Your site is referenced to OSGB British National Grid, right?
Your drawing didn't have an Assigned Projection, but if you use MAPCSASSIGN, you can manually give your map the coordinate system known as EPSG 27700 (OSGB1936.NationalGrid) then turn on Bing Aerial to verify the geospatial position. See image-201.
Image-201. MAPCSASSIGN the projection EPSG 27700 to get Bing imagery.
Once the geospatial position is established, you may use MAPREFERENCELAYOUTSYSTEM command to create a Grid linked to the viewport on your Layout Tab. See image-202. The Grid can have 'cells' sized 100meters X 100meters, or any cell height/width you want. The cell size you choose is under your control when using this command. See image-203.
Image-202. Go to Layout Tools Tab.....
Image-203. .......control settings for cell size.
If you assign the projection EPSG 27700, then the graticules (ticks and labels) can be linked so they're consistent with the northings and eastings values of the projection. Since both the ticks and labels are linked to the assigned projection, panning (or zooming) of your VP will update the coordinate values that surround your VP. See image-204 and image-205.
Image-204. Northing and easting values are 'LINKED' to the viewport AND your assigned coordinate system.
Image-205. North and Easting values are automatically updated when the VP is moved to SW. Compare values with Image-204.
You are correct when saying the original author's object data is linked to a reference grid in his modelspace, not his paper space layouts. However, his modelspace grid and the objects linked to it are not part of the typical Map3D toolset.
Regarding his Object Data, experienced Map3Der's can create Object Data in various ways. If you upload the original drawing and any Access/Excel file, then a thorough evaluation can be undertaken and a viable workflow can be provided for your specific drawing. Can you upload the original drawing and associated data files? Or privately share them through DM?
Chicagolooper
