Handrail problems on vintage Spectrum

[TRAINUT]

Help! I finally have a layout to run them on, so when I unboxed by 15-year-old Spectrum 8-40CWs in the Conrail paint scheme, I noticed I have to apply the handrails separately, which is no big deal until I discovered that the small tabs at the bottom of the stanchions would not fit into the matching holes on the side sills. Am I doing something wrong? I tried widening one of the holes slightly with an X-acto knife, but then figured out width was not my problem, depth was. Is there a trick to this I can't figure out? I would like to get these up and running soon.

[Trainman203]

Pin vise and appropriate small drill bit