Next step, a metric shit-ton of sanding so as to be able to fit 5.1mm dowels into 4.75mm holes. Sanded inside the holes with roll of sandpaper on the handle of a modelling file:

Click image for larger version. 

Name:	photo_2020-03-01_03-02-54.jpg 
Views:	391 
Size:	150.5 KB 
ID:	33988

...plus a bit of careful sanding of the dowels, trying to keep them as close to round as possible. After what felt like a week of sanding, and two blistered thumbs, they went in with encouragement from a mallet (I'd deliberately cut them a few mm long):

Click image for larger version. 

Name:	photo_2020-03-01_03-05-14.jpg 
Views:	376 
Size:	149.3 KB 
ID:	33989

A spot of normal sanding, and they're done!

Click image for larger version. 

Name:	photo_2020-03-01_03-06-10.jpg 
Views:	390 
Size:	160.0 KB 
ID:	33990