Mainship port lights

[Bilgewater]

I need to replace the four original ports on our 1978 34 Mk1 trawler. I believe they are made by Beckson, but I'm not sure how to measure to get the proper size. The "glass" area is 7 x 14 in the galley and head, and 6 x 12 in the forepeak. Is this the right measurement, or is it the overall dimensions?

Thanks

[newbernbuck]

The standard ones from Beckson were model 714 in galley and 512 in vberth.
Be aware that some folks updated to "rain drain" models that notches cut outs on bottom. You can still get individual parts like lens and gaskets if needed. their website is informative.

[jleonard]

When I had my 78 Mainship I, I replaced both of the larger ports. I used Becksons from Defender, and they fit the hole exactly, however several of the holes did not line up. Just a minor issue.
I don't recall the part number but Newbern is probably correct if the sizes match up.
Getting the screws and barrel nuts out was a challenge.
Just remember that the 78 model year boats were built differently than the 79 and newer ones. There are quite a few differences.