I am after a clarificationof the two types of what is often referred as marriage visas.

Firstly seems to bea visa Issued by immigration inside Thailand based on marriage, in General, themain requirements being proof of living together, initial and renewal extensionof stay applications 400k in a Thai bankin the Farlang name only for a period of 2 or 3 months or a income, somewherein the world of 40k a month for the preceding 2 months, then a 90 day report isneeded and if you wish to go out of Thailand you need a 1000b permission forre-entry.

The second is a multi entry non immigrant O visa valid for one year based on aThai marriage, which is valid for 1 year, but only permitted to enter the kingdomfor 90 days at a time. It is common for a person to do a border run and then doone just before the 1 year is up, in effect extending it to nearly 90 days overthe 1 year. The only Embassy in theregion to issue the multi entry visas is KL which require 100k in a Thai bankaccount.

My Question is, Are these multi entry nonimmigrant O visa valid for one year based on a Thai marriage from KL able to beextended or issued again for another year?

Technically there is no such thing as a "Marriage Visa". There is the one year "Extension of Stay" based on marriage to a Thai obtained within Thailand and a one year Non-Immigrant "O"(Other) Visa. The Multi-Entry Non-Immigrant "O" Visa from KL, or anywhere else for that matter, can be extended if a person meets the requirements, also not necessary to have a mutli-entry, a single entry will do if the financial and other requirements are met.

As said, you have two options: either you extend your stay in Thailand itself and show an income of 40,000 a month OR 400,000 in the bank in Thailand. Next year you extend again.

The other option is to go abroad and get a new visa. In the region only KL will issue a multiple (Penang is a maybe), but you will have to show 100,000 in the bank. Once the multiple visa is used up you can apply for a new visa.

The 40k a month income, is the the one for the last 2 months that the the Farlangs Embassy in BK gives a letter about?

The letter from the embassy is to confirm your income from abroad if you chose that option. Your embassy decides what they will accept as evidence.

No need to receive your income in Thailand.

I got a 12 month multi in Georgetown just two months ago,

I had all the paperwork but had no time to have my embassy verify my income.

It cost about 6,000 baht all up if I remember right.

Kenny