parts needed

I am looking to replace old electric luights parts.

Pool built in 1970"s…American Products Los Angeles

Here are needed parts

Exterior ring OD 12 inches, 10 holes spaced apart 3.5 inches

Niche cuurent stainless steel one is 6" high 8.5 OD

I have enough electric wire as electrician cut off at Niche so need to graft with underwater connection ( hopefully this exists)

Existing glass 8 1/4 inch OD (probably does not need replaced)

Can you assist?