I will do my best! Parts: Revell/Monogram 1/48 Nose parts and HK Models clear parts: https://www.scalemates.com/kits/hk-models-01f008-b-25j-mitchell--1438555
According to my eBay order, the grey parts are "Nose Guns B25J Mitchell 1:48 Scale Model Plane Part Revell" so a later version of the kit that was parted out, possibly from the '90s, whenever they had switched from OD Green to Grey plastic. Here's the page on eBay: https://www.ebay.com/itm/156281779845 and cost me US $15.68.
So far the fit of the greenhouse to the grey part is really decent after I trimmed it down to fit the profile of the greenhouse bottom edge. There is a slight width difference but we are talking 0.5mm to 1mm and easily managed by when gluing in place and taping till cured, from what I can see. The height before trimming down the grey was about 1mm to 1.5 mm higher than the fuselage front on the nose where it mates.
The clear parts from eBay is from "HK Models 1/48th Scale B-25J Mitchell - Clear Parts from Kit No. 01F008" according to that seller. No page sadly. That set me back $36.98. A fair amount of flash trimming on the grey parts due to the old school molds they used. The Clear parts, no flash at all, good fit, very little manipulating to make it fit. The only thing I ended up having to sand to fit was the grey nose to the existing model, about 0.25mm give or take to make it blend. (pilots side only, copilots side was good, it was subtly mis-molded on pilots side.)
Hope this helps, got a fair amount of work ahead of me now.