Identifying, Updating, and Painting a Bucket of 90's Era 40K Orks with Lawnor

I was handed a bucket of 40k orks many years ago and as I’ve nearly painted everything else I own its time to get these guys in order so I can paint them when the time comes. I do not know 40k so I don’t know my Goffs from my Evil Sunz, or my Snotlings from my Gretchins. I need help and advice with a lot of basics to understand what I have and to prevent me building and painting something I may wish to undo later.

I will lay out what I have, and what information I have on it along with any questions specific to that model.  In general, the questions I have are:

• What is the current standard base size for this model (They don’t appear to be listed on the GW site).  Doing a little reading online makes base size sound like personal preference which sounds crazy to me.  What size bases come in the box for these models?
• If it is a vehicle, does it need a base, and if so see previous question
• Do these models have current rules or current equivalent models, or have the been completely replaced, or been removed from the game
• Where weapon options are a thing is there anything I should know before gluing anything together?  Anything from my pile-o-guns that I should or should not include?
• Is anything here actually worth money that I should be aware of before I do anything to it that can’t be undone
• Is there a difference between standard Ork Boyz and Goff Nobs, Evil Suns etc, or are they the same unit just from different clans so just a different look?
• Links to painted versions of these old sculpts will be appreciated as they can help me work out what each part of the model is a little easier, along with giving advice on colour schemes, although I hope to try and bring them in line with the current schemes.

These models are from around 1990 and I am told that the weapons in the pile are no longer allowed by Orks.  I know I can play and paint how I like and any friend I play with will likely accept my minis are what I say they are.  However, should there come a time I want to start attending events could I run in to a situation where I get turned away as my models aren’t WYSIWYG if I build with these guns?  If so, can anyone suggest somewhere I can get replacements, bearing in mind I live in the UK and I’ll be looking for a cost effective solution.  Money is an issue.  I’d also be interested to hear if buying a box of new Ork Boyz might supply me with enough weapon options that I could build the new stuff and re-equip these old guys too.

The below pile of limbs contains:

36 empty left arms

37 empty right arms

4 right arms holding bolters

4 Plasma guns (Pistols?)

1 Dagger (bayonette?) and 2 broken blades

21 Bolt Pistols?

25 Bolters

1 Flama Lasgun Bolta

Guns identified as:

A: Bolta Lasgun Stubba Stubba

B: Eavy Bolter (Thanks, andre77)

C: Multi Melta (Thanks, andre77)

D: Blunderbuss Bolta Bolta

E: Shotgun Stubba Bolta

F: Auto Cannon (Thanks, andre77)

G: Autokannon Bolta Bolta

Last few identified on http://www.collecting-citadel-miniatures.com/wiki/index.php/Space_Orks_-_1995-6_Heavy_Weapons,_Kustom_Weapons_%26_Weirdboyz

Are these Snotlings or Gretchins? Is there a difference? Are they a unit, or part of another model, or base decorations?

A: Alternate turret hatch for Scorcher

B: : ???

C : ???

D: ???

E: ???

F: ???

G: ???

H: ???

I: ???

J: ???

K: ???

L: Runt with Stickk Bomb and Ammo Box

It appears these guys are Runts/Snotlings which pair up with a Runtherd. At least one of them matches up with the pic in the gallery below.

Known stats for Runts/Gretchins/Snotlings:
Unit size: 10-30 models with ranged weapons only

Base size in box today: Outpost says 25mm round bases
https://www.games-workshop.com/en-EU/Ork-Gretchin

Optional models: None